Question

Using the formula x = 2a + y, solve for y

Solve the following inequality: 13 – 2x ≥ 7

Solve using the addition principle: -8 + y = 17
y=

Answer 1

x = 2a + y
you want y by itself, so subtract 2a from both sides
x - 2a = y

13 - 2x >= 7
-2x >= 7 - 13
-2x >= - 6 (divide by -2 to get x by itself, but remember, when dividing/multiplying by a negative, changes the sign
x <= 3

-8 + y = 17
add 8 to both sides
-8 + 8 + y = 17 + 8 (what you do on one side of the equal sign, you have to do on the other side)
Now combine like terms
y = 17 + 8
y = 25

Answer 2

any questions ?

Answer 3

So 1st one x=2a
I always get confused when adding things to each side. it goes on both sides of the = sign correct ?

Answer 4

Sorry I meant y=2a for the 1st one ..