The first side of a triangle is 7cm shorter than twice the length of the second side.The third side is 4cm longer than the first side.

Question

The perimeter is 80cm.
Calculate the length of each side of this triangle.

Answer 1

So one side is x, while the next is 2x - 7, the third is 4cm longer than the first... the first was the 2x-7, so the third side is 2x - 7 + 4
P = s + s + s
80 = 2x - 7 + x + 2x -7 + 4
and solve for x, then sub that into the expressions for each side : )

Answer 2

How to solve the x

Answer 3

1) Gather your like terms on the right (that is, put your letters together, then your numbers)
2) Re-arrange the equation so that all of your numbers are on the left hand side.
3) Divide by whatever is connected to x on both sides... and hint... when you put the x's together you get 5x

Answer 4

I get 5x-10 what to do next

Answer 5

80 = 5x - 10
So take the 10 to the other side of the equation....

Answer 6

X=18 but what about the 2x

Answer 7

The side you are looking for is 2x that is 2 times 18
So the side is 2 x 18 = ....
The final side is 2x - 7 ... that is 2(18) - 7 = ....
That way you would have all three sides of the triangle labelled : )