4- 20
I created an equation for this one:
4x+x=100
- 4x= four times the amount of the other number
- x= the number
- combine like terms
5x=100
x=20
5. One pretzel costs $3
Create an equation:
Mulitply 2s+p=7 by -2 so you can use elimination.
Combine equations
p=3
Answer:
Step-by-step explanation:
(1) 2x - 6y = -12
(2) x + 2y = 14
There is a -6y and a +2y. Since they have opposite signs, I'll try to eliminate the y terms. (That's my choice. There is more than one way to solve these.)
Multiply eq. (2) by 3:
3x + 6y = 42
Then add the result to eq. (1) to eliminate the y terms:
2x - 6y = -12
3x + 6y = 42
------------------
5x = 30, so x = 6
Now plug the value of x into eq. (2) and solve for y:
6 + 2y = 14
2y = 8
y = 4
Why did I use eq. (2) to solve for y? Because it's less work. I could have used eq. (1) instead:
2(6) - 6y = -12
12 - 6y = -12
-6y = -24
y = 4
More than one way to solve.
X + y = 17
x - y = 29
x = 17 - y
x - y = 29
x = 17 - y
17 - y - y = 29
x = 17 - y
17 - 2y = 29
x = 17 - y
- 2y = 29 - 17
x = 17 - y
-2y = 12
x = 17 - y
y = -6
x = 17 - (-6)
y = -6
x = 17 + 6
y = -6
x = 23
y = -6
Answer:
x = 6
Step-by-step explanation:
