answer: 7
step-by-step:
okay so first you do 7*5 which is 35 and 20+8 which is 28
then you get 35=28+x (the x is the ‘missing number’)
to find x you subtract 28 from both sides to keep the equation balanced
35-28=28-28+x
so 35-28 is 7 and 28-28 is 0 so then you have 7=x and your answer is 7
you’re doing algebra but instead of using variables your teacher is saying find the ‘missing number’ haha