Answer:
y = -7x + 17
Step-by-step explanation:
you want to isolate the 'y' variable, start by distributing -7 on the right side
y + 4 = -7x + 21
now subtract 4 from each side
y = -7x + 17
Answer:
The volume of water and air inside each of the plastic ice cubes is 3000mm³
Step-by-step explanation:
This problem bothers on the mensuration of solid shapes, rectangular pyramid.
The volume of a rectangular pyramid is expressed as
V=(l*w*h)/3
Given data
Length l = 20mm
Width w= 15mm
Height h= 30mm
Substituting our given data we have
V= 20*15*30/3
V= 9000/3
V= 3000mm³
3x + 9 = 90
3x = 90 - 9 = 81
x = 81/3 = 27
x = 27