Question

to solve the following linear system by elimination, Brent first multiplied each equation by 10 explain why he did that. complete the solution. 0.3x-0.5y=1.2 and 0.7x-0.2y=-0.1

Answer 1

1. First you multiply by 10 to get rid of the decimals
3x - 5y = 12 and 7x - 2y = -1

2. Since we need to solve by elimation, we want to elimanate a variable. To do that multiple the first equation by 2 and the second equation by -5
 6x -  10y = 24
-35x +10y = 5

3. Add the equations downwards
-29x = 29

4. Divide both side by -29
x= -1

5. Solve for y by putting -1 in for x into any of the equations.  I'll use 3x- 5y=12

3(-1) -5y = 12
-3-5y=12
-5y =15
y= -3