Intermediate Algebra (Math)
posted by Lyri on .
Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this.
-2x Ð 8y = 22
-6x Ð y = 20
At first I tried to multiply by 8 but that did not work.
I assume the illegible sign is a + sign, since the - sign shows clearly.
-2x + 8y = 22 ....(1)
-6x + y = 20 ....(2)
First, we determine if the system has 0 solution, one solution or many solutions.
Calculate the determinant of the left-hand-side:
Since Δ≠0, the system has one solution. Multiplying 3*(-1) and add to (2) gives
solving for y gives
Substitute y=2 into either (1) or (2) to solve for x.
Then substitute both x and y in the remaining equation for a check.