Find the measure of angle B

∠B = 57

Step-by-step explanation:

interior angles of triangles are supplementary

∠A + ∠B + ∠C = 180

40 + ∠B + ∠83 = 180

123 + ∠B = 180

-123              -123

∠B = 57

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step-by-step explanation:

use that smart brain

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.