Answer:
x= -2/3y-4
Step-by-step explanation:
3x+2y=-12
3x+2y-2y= -2y-12
3x=-2y-12
3x/3= -2y/3-12/3
x= -2/3y-4
Answer:
x value: start with 0 and go up by 1
y value:start with 10 and each week is 5 more than previous week
Step-by-step explanation:
Create a proportion:
1 in/15 mi= x in/25 mi
15x=25
X is approximately 1.67 in
Answer:
- $8000 at 1%
- $2000 at 10%
Step-by-step explanation:
It often works well to let a variable represent the amount invested at the higher rate. Then an equation can be written relating amounts invested to the total interest earned.
__
<h3>setup</h3>
Let x represent the amount invested at 10%. Then 10000-x is the amount invested at 1%. The total interest earned is ...
0.10x +0.01(10000 -x) = 280
<h3>solution</h3>
Simplifying gives ...
0.09x +100 = 280
0.09x = 180 . . . . . . . subtract 100
x = 2000 . . . . . . divide by 0.09
10000 -x = 8000 . . . . amount invested at 1%
<h3>1.</h3>
$8000 should be invested in the 1% account
<h3>2.</h3>
$2000 should be invested in the 10% account
Answer:
1. x = 39.67
2. x = 15
3. x = 49.29
4. x = -12.8
5. x = 96
6. x = 42
7. x = 36
8. x = 0
9. x = 78
Step-by-step explanation:
Just remember to always isolate the unknown. Here are the solutions to your problem. I will explain each step for the first for you to give you an idea how the others were worked out.
1.
Add 2 to both sides to get rid of -2 on the left side.
![\dfrac{3x}{7}-2+(2)=15+(2)///dfrac{3x}{7}=17](https://tex.z-dn.net/?f=%5Cdfrac%7B3x%7D%7B7%7D-2%2B%282%29%3D15%2B%282%29%2F%2F%2Fdfrac%7B3x%7D%7B7%7D%3D17)
Multiply both sides by 7 to get rid of 7 on the left side.
![\dfrac{3x}{7}\times 7 = 17\times 7\\\\3x = 119](https://tex.z-dn.net/?f=%5Cdfrac%7B3x%7D%7B7%7D%5Ctimes%207%20%3D%2017%5Ctimes%207%5C%5C%5C%5C3x%20%3D%20119)
Divide both sides by 3 to get rid of 3 on the left side.
![\dfrac{3x}{3} = \dfrac{119}{3}\\\\x = 39.67](https://tex.z-dn.net/?f=%5Cdfrac%7B3x%7D%7B3%7D%20%3D%20%5Cdfrac%7B119%7D%7B3%7D%5C%5C%5C%5Cx%20%3D%2039.67)
You could also transpose everything by the x to the other side of the equation. Just remember that whatever OPERATION used on the original side, must be opposite on the other side. I'll use the second problem to show this.
![\dfrac{2x}{5}+1=7](https://tex.z-dn.net/?f=%5Cdfrac%7B2x%7D%7B5%7D%2B1%3D7)
Transpose 1 on the left to the right. It is addition on the left, then it would be subtraction on the other side.
![\dfrac{2x}{5}+1=7\\\\\dfrac{2x}{5}=7-1\\\\\dfrac{2x}{5}=6](https://tex.z-dn.net/?f=%5Cdfrac%7B2x%7D%7B5%7D%2B1%3D7%5C%5C%5C%5C%5Cdfrac%7B2x%7D%7B5%7D%3D7-1%5C%5C%5C%5C%5Cdfrac%7B2x%7D%7B5%7D%3D6)
Transpose 5 from the left side to the right. It is division on the left, then it would be multiplication on the right.
![\dfrac{2x}{5}=6\\\\2x=6\times 5\\\\2x=30](https://tex.z-dn.net/?f=%5Cdfrac%7B2x%7D%7B5%7D%3D6%5C%5C%5C%5C2x%3D6%5Ctimes%205%5C%5C%5C%5C2x%3D30)
Transpose 2 from the left side to the right. It is multiplication on the left, then it would be division on the right.
![2x=30\\\\x=\dfrac{30}{2}\\\\x=15](https://tex.z-dn.net/?f=2x%3D30%5C%5C%5C%5Cx%3D%5Cdfrac%7B30%7D%7B2%7D%5C%5C%5C%5Cx%3D15)
Let's move on with the rest now.
3.
![\dfrac{7x}{15}-1=22\\\\\dfrac{7x}{15}=22+1\\\\\dfrac{7x}{15}=23\\\\7x=23\times15\\\\7x=345\\\\x=\dfrac{345}{7}\\\\x=49.29](https://tex.z-dn.net/?f=%5Cdfrac%7B7x%7D%7B15%7D-1%3D22%5C%5C%5C%5C%5Cdfrac%7B7x%7D%7B15%7D%3D22%2B1%5C%5C%5C%5C%5Cdfrac%7B7x%7D%7B15%7D%3D23%5C%5C%5C%5C7x%3D23%5Ctimes15%5C%5C%5C%5C7x%3D345%5C%5C%5C%5Cx%3D%5Cdfrac%7B345%7D%7B7%7D%5C%5C%5C%5Cx%3D49.29)
4.
![\dfrac{5x}{8}+10=2\\\\\dfrac{5x}{8}=2-10\\\\\dfrac{5x}{8}=-8\\\\5x=-8\times8\\\\5x=-64\\\\x=\dfrac{-64}{5}\\\\x=-12.8](https://tex.z-dn.net/?f=%5Cdfrac%7B5x%7D%7B8%7D%2B10%3D2%5C%5C%5C%5C%5Cdfrac%7B5x%7D%7B8%7D%3D2-10%5C%5C%5C%5C%5Cdfrac%7B5x%7D%7B8%7D%3D-8%5C%5C%5C%5C5x%3D-8%5Ctimes8%5C%5C%5C%5C5x%3D-64%5C%5C%5C%5Cx%3D%5Cdfrac%7B-64%7D%7B5%7D%5C%5C%5C%5Cx%3D-12.8)
5.
![\dfrac{x}{6}+4=20\\\\\dfrac{x}{6}=20-4\\\\\dfrac{x}{6}=16\\\\x=16\times6\\\\x=96](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%7D%7B6%7D%2B4%3D20%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B6%7D%3D20-4%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B6%7D%3D16%5C%5C%5C%5Cx%3D16%5Ctimes6%5C%5C%5C%5Cx%3D96)
6.
![\dfrac{x}{3}-4=10\\\\\dfrac{x}{3}=10+4\\\\\dfrac{x}{3}=14\\\\x=3\times14\\\\x=42](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%7D%7B3%7D-4%3D10%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B3%7D%3D10%2B4%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B3%7D%3D14%5C%5C%5C%5Cx%3D3%5Ctimes14%5C%5C%5C%5Cx%3D42)
7.
![\dfrac{x}{6}+2=8\\\\\dfrac{x}{6}=8-2\\\\\dfrac{x}{6}=6\\\\x=6\times6\\\\x=36](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%7D%7B6%7D%2B2%3D8%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B6%7D%3D8-2%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B6%7D%3D6%5C%5C%5C%5Cx%3D6%5Ctimes6%5C%5C%5C%5Cx%3D36)
8.
![\dfrac{x}{9}+8=8\\\\\dfrac{x}{9}=8-8\\\\\dfrac{x}{9}=0\\\\x=0\times9\\\\x=0](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%7D%7B9%7D%2B8%3D8%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B9%7D%3D8-8%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B9%7D%3D0%5C%5C%5C%5Cx%3D0%5Ctimes9%5C%5C%5C%5Cx%3D0)
9.
![\dfrac{x}{6}+7=20\\\\\dfrac{x}{6}=20-7\\\\\dfrac{x}{6}=13\\\\x=13\times6\\\\x=78](https://tex.z-dn.net/?f=%5Cdfrac%7Bx%7D%7B6%7D%2B7%3D20%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B6%7D%3D20-7%5C%5C%5C%5C%5Cdfrac%7Bx%7D%7B6%7D%3D13%5C%5C%5C%5Cx%3D13%5Ctimes6%5C%5C%5C%5Cx%3D78)