1/2(6x+4)+2/3(-3x+9)=21 pls

X=13

Step-by-step explanation:

1). Factor the expressions

1/2*2(3x+2)+2/3*3(-x+3)=21

2). Reduce the numbers

(3x+2)+2(-x+3)=21

3). Rewrite & Remove parentheses

3x+2-2x+6=21

4). Collect the like-terms & Calculate

x+8=21

5). Move the constant to the right

x=21-8

6). Calculate

x=13

step-by-step explanation:

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240