10 because 7 x 3 = 21 and 7 + 3 = 10 so your answer is 10
Answer:
12 sandwiches
Step-by-step explanation:
If 3 sandwiches cost $20
Then x sandwiches cost $80
3----20
x----80
20x=3 x 80
20x=240
x=240/20
x=12 sandwiches
There is no answer to this in Geometric Sequence. Please check the question and type it again. I am not writing this to gain points, I already have a lot, but to let you know that there is no sequence for this question.
Hope it's clear to you:)
P = 2w + 2h
factorise
P = 2 (w + h)
divide both sides by the coefficient of w + h
P ÷ 2 = 2 (w + h) ÷ 2
P/2 = w + h
make w the subject of the formula
w = h - p/2