Question

In ΔCAB, if m∠A = 10x + 9, m∠B = 34°, and m∠C = 97°, what is the value of x?

Answer 1

x = 4

Here is why:

When adding up all angles of a triangle, they will be equal to 180.

Let's add ∠B and ∠C together.

$34+97=131$

Let's subtract it from 180, that will be the value of ∠A.

$180-131=49$

Now we can set ∠A equal to 49.

$10x+9=49$

Subtract 9 from both sides.

$10x=40$

Divide.

x = 4