What is the solution to the system? use elimination .
-18.6x+ 17.2y=90.2
14.2x+ 3.4y= -35.8
a.(3,2)
b.(-3,2)
c.(2/3,4/9)
d.(2,3)
IS IT D??
You've already been told it's not D.
Sub the numbers in for x and y.
what does sub the numbers mean ?? Please help.
@ms.sue
It means substitute the numbers for the unknown quantities.
-18.6x+ 17.2y=90.2
(-18x * 2) + (17.2 * 3) = 90.2
As another tutor told you, that doesn't work.
thank you. so I did that and is it b ?
Yes. B is right.
To solve the system of equations using elimination, you need to eliminate one of the variables by adding or subtracting the equations. In this case, let's eliminate the variable x.
Multiply the first equation by 14.2 and the second equation by -18.6 to make the coefficients of x in both equations the same:
-18.6 * (-18.6x + 17.2y) = -18.6 * 90.2
14.2 * (14.2x + 3.4y) = 14.2 * (-35.8)
Simplifying, we get:
341.2x - 316.72y = -1678.92
201.64x + 47.48y = -509.16
Now, add the two equations together to eliminate x:
(341.2x - 316.72y) + (201.64x + 47.48y) = -1678.92 + (-509.16)
542.84x - 269.24y = -2188.08
Now, we can solve for y. Rearrange the equation to isolate y:
-269.24y = -2188.08 - 542.84x
y = (-2188.08 - 542.84x) / -269.24
Now substitute this expression for y into one of the original equations (let's use the first equation) and solve for x:
-18.6x + 17.2((-2188.08 - 542.84x) / -269.24) = 90.2
Simplify and solve for x:
-18.6x - 3059.84 - 17.2x = 90.2 * -269.24
-35.8x - 3059.84 = -24348.248
Move the constant term to the other side:
-35.8x = -24348.248 + 3059.84
-35.8x = -21288.408
Divide both sides by -35.8 to solve for x:
x = -21288.408 / -35.8
Now, substitute the value of x back into one of the original equations (let's use the second equation) to solve for y:
14.2((-21288.408 / -35.8)) + 3.4y = -35.8
y = (-35.8 - 14.2((-21288.408 / -35.8))) / 3.4
Calculate this expression to find the value of y.
After finding both x and y, we can identify the solution to the system of equations.