If cos∠b = sin∠a and m∠a = 32°, what is the measure of ∠b?
32
58
90
148
not sure if its 58 or 90 but and explain why !

  58

Step-by-step explanation:

Consider the right triangle ABC, with C as the right angle. The sides opposite those angles are a, b, c, where c is the hypotenuse.

The mnemonic SOH CAH TOA tells you

  Sin = Opposite/Hypotenuse

  Cos = Adjacent/Hypotenuse

so, ...

  sin(A) = a/c

  cos(B) = a/c = sin(A)

We know that in a right triangle, angle A and angle B are complementary. So, if angle A is 32°, angle B will be 90°-32° = 58°.

8(-10x+3.5y-7)

8×-10x + 8×3.5y + 8×-7

-80x + 28y - 56

therefore

-80x+28y-56 is the correct answer