Question

0.01x - 0.3y = 1

y = 0.1x - 2

Which of the following systems is equivalent to the given system?

A) x - 30y = 100 and 10y = x - 20
B) x - 3y = 10 and 10y = x - 20
C) 10x - 30y = 10 and 10y = x - 20

Answer 1

Explanation:

0.01x−0.3y=1;y=0.1x−2

Rewrite equations:

y=0.1x−2;0.01x−0.3y=1

Step: Solvey=0.1x−2for y:

y=0.1x−2

Step: Substitute0.1x−2foryin0.01x−0.3y=1:

0.01x−0.3y=1

0.01x−0.3(0.1x−2)=1

−0.02x+0.6=1(Simplify both sides of the equation)

−0.02x+0.6+−0.6=1+−0.6(Add -0.6 to both sides)

−0.02x=0.4

−0.02x

−0.02

=

0.4

−0.02

(Divide both sides by -0.02)

x=−20

Step: Substitute−20forxiny=0.1x−2:

y=0.1x−2

y=(0.1)(−20)−2

y=−4(Simplify both sides of the equation)

Answer:

x=−20 and y=−4

Answer 2

x-30y=100 and 10y=x-20

Explanation: