Solve each of the following systems by using either addition or substitution. If a unique solution does not exist, state whether the system is dependent or inconsistent.
10x + 2y = 7
y = -5x + 3
2007-03-28 12:43:57 · 3 answers · asked by materialtam 1 in Education & Reference ➔ Homework Help
10x + 2y = 7
y = -5x + 3
You know what y equals so just put it into the first equation like this: 10x + 2 (-5x + 3) = 7
10x + -10x + 6 =7
To be honest the 10x + -10x cancels and confuses me. My guess is that this is an inconsistent system. The values of x and y can never be the same for both sets because the X's canceled.
2007-03-28 12:57:01 · answer #1 · answered by JimBob 6 · 0⤊ 0⤋
Look only at the first equation. Everywhere you see a y, replace it with some parentheses.
10x+2() = 7
Now put the right hand side of the second equation into those parentheses.
10x + 2(-5x + 3) = 7
Now solve for x.
10x - 10x + 6 = 7
6 =7
Since 6 = 7 is false, no solution exists. The system is inconsistent.
Here you used the method of substitution, for the second equation tells you what y is in terms of x.
2007-03-28 19:56:04 · answer #2 · answered by 1,1,2,3,3,4, 5,5,6,6,6, 8,8,8,10 6 · 0⤊ 0⤋
I am doing thte same thing in school and I am lost as well.
2007-03-28 19:47:40 · answer #3 · answered by Anonymous · 0⤊ 0⤋