Math Help??? Solve by elimination.?

Question

3x + 2y = -12
4x + 5y = -23

Help please???

Answer 1

3x + 2y = -12
4x + 5y = -23

Multiply the top equation by 4, and the bottom equation by 3. So the system of equation now becomes:

12x + 8y = -48 (equation 1)
12x + 15y = -69 (equation 2)

Now substract the first one from the second one, i.e. equation 2 - equation 1:

We get: 0x + 7y = -69+48
7y = -21
Divide both sides by 7
y = -21/7
y = -3

So substitute y=3 into any of the equations to find x. Let's use equation 1(the original one):
3x + 2*(-3) = -12
3x - 6 = -12
Add 6 to both sides:
3x = -12+6
Divide both sides by 3:
x = -6/3 = -2

So our Final Answer is:
x=-2
y=-3

Answer 2

3x + 2y = -12 (1)
4x + 5y = -23 (2)

4(1):
12x + 8y = -48 (3)

3(2):
12x + 15y = -69 (4)

(3) - (4):
12x + 8y -(12x+15y)= -48 +69
-7y=21
=> y=-3
from(1):
3x-6=-12
3x=-6
=>x=-2

x=-2, y=-3

check my working but method is right!

Answer 3

3x + 2y = -12 (i)
4x + 5y = -23 (ii)
To eliminate the x terms, add 4(i) & (-3)(ii):
12x + 8y = - 48
-12x - 15y = 69
-----------------------
-7y = 21
y = -3.
3x + 2(-3) = -12
3x = -6
x = -2.

Answer 4

multiply 4 to eqn 1 n 3 to eqn 2

we get

12x + 8y = -48
12x + 15y= -69

subtract these

we hav
-7y = 21
=> y=-3

substitute value of y in eqn 1 or 2

we getx= -2

Answer 5

12x + 8y = - 48
-12x - 15y = 69----ADD

- 7y = 21
y = - 3

3x - 6 = - 12
3x = - 6
x = - 2

x = - 2, y = - 3