A regular triangular pyramid has a base area of 31.5 mm2
and a surface area of
252 mm2. What is the lateral area of the regular triangular
pyramid?

maybe do the math

Step-by-step explanation:

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so:

40 minutes

step-by-step explanation:

add the time and multiply by 2