Answer:
y = 18
a = -2
Step-by-step explanation:
Hello There!
For the first one we need to create an equation to solve for y
23+7=y+12
30=y+12
isolate the variable using inverse operations
subtract 12 from each side
30-12=18
we're left with y = 18
for the second one we need to create an equation to solve for a
3+15+a=8+8+8
3+15=18
8+8+8=16
16=18+a
step 1 subtract each side by 18
16-18=-2
we're left with a = -2
