A About what percent of the total number of cars are hopper cars? B About what percent of the total number of cars are gondola or
Cars i
Gondola ca
T
Tank car

15

step-by-step explanation:

we are given the following expression and we are to solve it and find the product:

-13 × (-5)

solving the given expression in the standard order of solving a mathematical expression, beginning with the opening of brackets and then multiplying the terms and changing their signs.

-3 × -5 = 15 (answer is positive because when negative is multiplied with negative, it gives a positive answer)

225x²+4=0

225x²=0-4

225x²=-4

x²=-4/225

x=±√-4/225

41*67/2=1373.5

step-by-step explanation:

i just used a calculator

answer: x=3 and y=4

step-by-step explanation: