(a)
= 400
(b)
(c) Only the positive solution makes sense because you cannot have a negative side length.
(d) Since one side of the painting is 20 inches, all four sides together will be 20*4 = 80 inches
Length=x
Width=4x
4x•x=400 sq cm
x= 10 cm
4x= 40 cm
P=2•10cm+2•40 cm
=100 cm
Answer: see below
Step-by-step explanation:
3x-12=7x+8 ⇔ given
-12=4x+8 ⇔ addition property of equality
-20=4x ⇔ subtraction property of equality
x=-5 ⇔ division property of equality
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5(x-1)=4x+13 ⇔ given
5x-5=4x+13 ⇔ distributive property
x-5=13 ⇔ subtraction property of equality
x=18 ⇔ addition property of equality