Final answer:
To find the value of m∠C, set the expression for m∠E equal to the expression for m∠C and solve for x. The value of m∠C is -60 degrees.
Step-by-step explanation:
To find the value of m∠C, we need to set the expression for m∠E equal to the expression for m∠C and solve for x. So, we have (x-10) = (2x+40).
First, we simplify the equation by combining like terms: x - 10 = 2x + 40. Then, we can solve for x by subtracting x from both sides of the equation: -10 = x + 40. Finally, we isolate x by subtracting 40 from both sides of the equation: -50 = x.
Now that we have the value of x, we can substitute it back into the expression for m∠C: m∠C = 2x + 40 = 2(-50) + 40 = -100 + 40 = -60 degrees.