71 and 72 please help.

Mathematics

1 answer:

Hitman42 [59]3 years ago

5 0

71) The triangle is isos. so the base angles are congruent

2a+b=5b-3a
5a=4b

The angles of a triangle all add up to 180

180=5a -2b + 2a +b + 5b -3a
180=4a+4b

Substitute 4b with 5a

180=4a+5a
180=9a
a=20

And substitute a into the equation: 5a=4b to solve for b and solve for the measurements of the angles

72) Angles that are supplementary add up to 180

8(y-x)+124=180
9x-2y+124=180

8x-8y=56
(9x-2y=56)4

Use elimination to solve for the variables

8x-8y=56
-(36x-8y=224)
-28x=-168
x=48

Substitute x into the other equation to solve for y and find the measurements of the angles

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