A-2b=-10
add 2b on both sides
a=2b-10
add 10 to both sides
a+10=2b
divide both sides by 2
a/2+10/2=a/2+5=b
b=5+a/2
R/9 = -21
Multiply by 9
r = -189
Answer:
4L-12
Step-by-step explanation:
let's assume the length = L
then the width of the rectangle is L - 6
perimeter = 2× (a+b)
where "a" and "b" are the length and the width of the rectangle.
so perimeter = 2× (L + L - 6)
2 × ( 2L - 6)
4L - 12
