YolieBear
Answered

At Westonci.ca, we make it easy for you to get the answers you need from a community of knowledgeable individuals. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform. Connect with a community of professionals ready to help you find accurate solutions to your questions quickly and efficiently.

how do you solve y=2x+7; 3x-y=-9 using substitution method. Explain please!!

Sagot :

The y's value is given in the first equation. [tex]y=2x+7[/tex] . Now to solve, we will, plug it's value in the second equation.

[tex]3x-(2x+7)=-9\\ \\ 3x-2x-7=-9\\ \\ x=-9+7\\ x=-2\\ [/tex]

Now we have x's value, we will plug it's value in the first equation.(We can plug it in the second one too, but plugging it the first one will make it easier.)

[tex]x=-2\\ y=2x+7\\ y=2\cdot -2+7\\ y=-4+7\\ y=3[/tex]
{ y = 2x + 7
{ 3x - y = - 9

Substitute y for 2x + 7 in the 2nd equation:

3x - y = - 9
3x - ( 2x + 7 ) = - 9
3x - 2x - 7 = - 9
3x - 2x = - 9 + 7
x = - 2

Substitute - 2 for x in one of the equations:

y = 2x + 7
y = 2.( - 2 ) + 7
y = - 4 + 7
y = 3

S = { - 2 , 3 }
Thank you for your visit. We're dedicated to helping you find the information you need, whenever you need it. Thank you for visiting. Our goal is to provide the most accurate answers for all your informational needs. Come back soon. Get the answers you need at Westonci.ca. Stay informed by returning for our latest expert advice.