What is the value of ▲ in the equation shown? 7x9 = (7x10) - (7x▲)

The correct answer is it equals 1

Assuming the x means multiply

evaluate parenthsees fist

7x10=70

-7x?=-7?

7x9=63

so

63=70-7?

minus 70 both sides

-7=-7?

divide both sides by - 7

1=?

an eaier way to do it is

regocnize we can undistribute the 7 because

ab-ac=a (b-c)

so

(7x10) - (7x?) = 7 (10-?)

now we got

7x9=7 (10-?)

divide both sides by 7

9=10-?

minus 10

-1=-?

times - 1

1=?

it is 1