Which equation can be used to find 42 x 51? (4 x 5) + (2 X 1) = 20 + 2 (40 x 50) + (40 x 1) + (2 x 50) + (2 x 1) = 2,000 + 40 + 100 + 2 (4 x 5) + (4 x 1) + (2 x 5) + (2 x 1) = 20 +4+10+ 2 (40 x 50) + (2 x 1) = 2,000 + 2

the solution is 12x-6y

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:

$15 each

step-by-step explanation:

$45/3 children= $15 each

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92