John is twice as old as Mary. The sum of their ages is 21. How old is Mary?
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Answer:
Step-by-step explanation:
Hello There!
The shown figure is a parallelogram
If you didn't know the opposite angles of parallelograms are congruent ∠A≅∠C and ∠B≅∠D
so we can set up an equation to solve for w
because ∠B≅∠D we use this equation
14w + 50 = 28w - 45
now we solve for w
step 1 add 45 to each side
-45+45 cancels out
50 + 45 = 95
now we have 14w + 95 = 28w
step 2 subtract each side by 14w
28w-14w=14w
now we have 14w = 95
step 3 divide each side by 14
14w/14=w
we're left with
