odnfodsnf odnfodsnf

05-07-2016
Mathematics

contestada

3x-y=7
9x-3y=21

how do I do it by the substitution method i think so.?

Respuesta :

ayeKassandra ayeKassandra

05-07-2016

3x-y=7
9x-3y=21

9x-3y=21

Put the equation into slope intercept form so that you can later substitute it into 3x-y=7.

9x-3y=21
-9x. -9x

-3y=-9x+21
Divide each number by -3.
You get y=3x-7

You will substitute y for 3x-7 in 3x-y=7

Solve:
3x-(3x-7)=7
3x-3x+7=7
0+7=7
7=7

This means that both equations are the same.

Answer Link

Otras preguntas

Insert parenthesis () to make the following problem true: 3+6-2x4=19

Need help with this

one x-intercept for a parabola is at the point (2, 0). use the quadratic formula to find the other x-intercept for the parabola defined by y=x^2-3x+2

gold is the king of metal why??

How have women and other artists formerly excluded from galleries and museums used "crafts" to express their unique vision and gain acceptance into the world of

Find the directional derivative of the function at the given point in the direction of the vector v. f(x, y, z) = xey + yez + zex, (0, 0, 0), v = 5, 2, −2

Capital structure decisions include all of the following EXCEPT: Deciding how to pay for long term projects. Deciding the mix of debt and equity for the firm. D

he most important factor in decreasing the intracellular concentration of calcium ion after contraction is A) active transport of calcium across the sarcolemma.

what are bonds that hold two amino acids together called

Which expression is a sum of cubes?