Help, please the question and thank you

test math

Equation : 7x = 84

or, Equation : 90+5x-6+2x+12 = 180

(I am confused if there should be the whole equation or shortened one. It's either one of them)

m<H = 54

m<I = 90

m<J = 36

Step-by-step explanation:

90+5x-6+2x+12 = 180 (sum of triangle)

or, 102-6+7x=180

or, 7x = 84

or, x = 12

now

5x-6 = 5×12-6 = 60-6 = 54

2x+12 = 2×12+12 = 24+12 = 36

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.