Question

Help me with this assignment please..

Solving Systems of Linear Equation by Subtitution

3a+6b= -10
b=-2a-5

Answer 1

replace b in equation 1 by
\[-2a-5\] and don't forget the parentheses you get
\[3a+6(-2a-5)=-10\]

Answer 2

latex not working?

Answer 3

3a+6b= -10 replace -2a-5 instead of b in the 1st eq
b=-2a-5

3a+6(-2a-5)=-10
3a-12a-30+10=0
-9a=20a=-20/9

b=-2*(-20/9)-5

Answer 4

substitute -2a-5 into the first equation
and it will become
3a+6(-2a-5)=-10
3a-12a-30=-10
-9a=20
a=-20/9

Answer 5

how about for the "b"..?

Answer 6

substitute the answer for a back to the equation, b=-2a-5