Evaluate -7 5/8 + (-6 1/4)

exact form:

-111/8

Decimal form:

-13.875

Mixed Number Form:

-13 7/8

-5.875

Step-by-step explanation:

primero se resuelve el paréntesis

1/4 =0.25

y se multiplica por el -6

0.25x-6= -1.5

luego se resuelve el otro lado

primero dividimos

5/8=0.625

y se multiplica por -7

0.625x-7= -4.375

y para finalizar se suman los dos lados

-4.375 + -1.5

= -5.875

(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