Answer ! to solve the system of equations below, luanne isolated the variable y in the first equation and then substituted it into the second equation what was the resulting equation ?
{2y=6x
{x²+y²=49
a. x²+9x²=49
b. x²+9x=49
c. x²+3x=49
d. x²+3x²=49

Option A. x² + 9x² = 49

Step-by-step explanation:

Luanne used two equations given as 2y = 6x (1)

and x² + y² = 49 (2)

Luanne isolated the value of y from the equation 1 and then substituted in equation 2.

We will do the same.

from equation 1

2y = 6x

⇒ y = 3x

Now we plug in the value of y in equation 2.

x² + (3x)² = 49

x² + 9x² = 49

which matches the option A.

which expression represents the approximate length of bc?

step-by-step explanation:

a

step-by-step explanation: