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Two angles are complementary. One angle is ten less than four times the other angle. Find the measure of the larger angle

A.20
B.70
C.38
D.142

1 Answer

2 votes

Answer:

B.70

Explanation:

For one or two angles are complementary angle(s), they have to equal 90°.

So, we need to find the larger angle, but what about the other?

Let x be the other angle and y be the angle we are looking for

x + y = 90

Lets look for x first, since one angle is ten less than four times the angle we are looking for or visa versa, we must:

y = 4x - 10

For an exchange, lets take out the y variable for another x variable:

So now we should have x + 4x - 10 = 90

Combine like terms and do cross equation :

x + 4x -10 = 90

5x - 10 = 90

Add 10 to both sides:

5x = 100

100/5 = 20

So x=20

Now for y which is what we are looking for,

y = 4x - 10

Since x is 20, plug it in

y = 80 - 10

y=70 is our larger angle

User EyalG
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