They are similar by number. But they are not perpendicular. 3x+4y=12 gives you a negative slope. But 4x-3y gives you a positive slope. So they would be crossing each other if put together. This means that Sadia is correct and Henri isn’t. Show all work: 4x-3y=12
4x-3y+3y=12+3y
4x=3y+12
4x/4=3y+12/4
X=3/4y+3
3x+4y=12
3x+4y+-4y=12+-4y
3x=-4y+12
3x/3=-4y+12/3
X=-4/3y+4
15. 
Add "g" on both sides

Multiply 5 on both sides to get x by itself
x = 5(a + g)
x = 5a + 5g
18. a = 3n + 1
Subtract 1 on both sides
a - 1 = 3n
Divide 3 on both sides to get n by itself
= n
21. M = T - R
Add "R" on both sides to get "T" by itself
M + R = T
24. 5p + 9c = p
Subtract "5p" on both sides
9c = p - 5p
9c = -4p
Divide 9 on both sides to get "c" by itself
c =
or c = 
27. 4y + 3x = 5
Subtract "4y" on both sides
3x = 5 - 4y
Divide 3 on both sides to get "x" by itself
x = 
x = 
The X coordinate has to be 0
Answer:
3. 42
4. 38.7
Step-by-step explanation: