Answer:
Step-by-step explanation:
sales tax on the shirt= 20(0.09)=1.8 dollars
total cost with sales tax =20+20(0.09)=21.8$
Answer:
(-4,2)
Step-by-step explanation:
First we have to find a common multiple to use to add and find the system of equations. We need to eliminate one of the variables in order to solve.
Since 5 * 3 = 15, and 3 * -5 = 15, -15x and 15x will cancel each other out. Therefore x will be eliminated.
Before:
5x + 2y = -16
3x + 7y = 2
After:
15x + 6y = -48 <----------Now we solve for y
-15x + -35y = -10
+----------------------
-29y = -58
-29 -29
y = 2
Now what we do is we choose and equation and solve for x, since it is still unknown. Any equation is fine but I will choose the second one since it has easy numbers.
3x + 7y = 2
3x + 7(2) = 2
3x + 14 = 2
-14 -14
----------------------
3x = -12
3 3
x = -4
Therefore our final answer is (-4,2)
Answer:
7 and 1
Step-by-step explanation:
Let the numbers be a and b.
<u>A positive number is 7 times another number:</u>
<u>If 3 is added to both the numbers then one of the new number becomes 5 by 2 times the other new number:</u>
<u>To solve this we substitute </u><u>a</u><u> with </u><u>7b</u><u> in the second equation:</u>
- 7b + 3 = 5/2 × (b +3) ⇒ multiplying both sides by 2
- 14b + 6 = 5b + 15 ⇒ collecting like terms
- 14b - 5b = 15 - 6
- 9b = 9
- b = 1 ⇒ solved for b
<u>Then, finding a:</u>
- a= 7b
- a=7*1
- a= 7 ⇒ solved for a
<u>So the numbers are</u> 7 and 1
Answer:
25
Step-by-step explanation:
4x+8+72=180
4x+80=180
180-80=100
100/4=25
x=25
