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??
Why do you ask if it is D ?
Did you sub in x=2 and y=3 ?
That would be the simple way to tell, it would take about 20 seconds with a calculator.
How tho and i was asking if it was right.
Sierra -- don't you know how to sub in the numbers for x and y?
First equation:
-18.6x + 17.2y = 90.2
your guess: D, x=2,y=3
so -18.6(2) + 17.2(3) = 90.2
-36.4 + 51.6 = 90.2
is 15.2 = 90.2 ?? , I guess not, so NOT D
To solve this system of equations using elimination, we need to eliminate one of the variables by adding or subtracting the equations. Let's start by multiplying the second equation by -1. This will allow us to eliminate the x variable.
Original equations:
-18.6x + 17.2y = 90.2
14.2x + 3.4y = -35.8
After multiplying the second equation by -1:
-18.6x + 17.2y = 90.2
-14.2x - 3.4y = 35.8
Next, add the two equations together to eliminate the x variable:
(-18.6x + 17.2y) + (-14.2x - 3.4y) = 90.2 + 35.8
-32.8x + 13.8y = 126
Now we have a single equation with one variable. We can solve for this variable, y:
-32.8x + 13.8y = 126
13.8y = 32.8x + 126
y = (32.8x + 126) / 13.8
Now we can substitute this value of y back into one of the original equations to solve for x. Let's choose the first equation:
-18.6x + 17.2y = 90.2
-18.6x + 17.2((32.8x + 126) / 13.8) = 90.2
Now we can simplify and solve for x:
-18.6x + (17.2 * (32.8x + 126)) / 13.8 = 90.2
-18.6x + (561.76x + 2188.8) / 13.8 = 90.2
Combining like terms:
-18.6x + (561.76x + 2188.8) / 13.8 - 90.2 = 0
Multiplying through by the denominator to get rid of the fraction:
-18.6x * 13.8 + (561.76x + 2188.8) - 90.2 * 13.8 = 0
-256.68x + 561.76x + 2188.8 - 1245.96 = 0
305.08x + 942.84 = 1245.96
Simplifying further:
305.08x = 1245.96 - 942.84
305.08x = 303.12
x = 303.12 / 305.08
x ≈ 0.993
Now that we have the value of x, we can substitute it into either of the original equations to solve for y. Let's substitute it into the first equation:
-18.6x + 17.2y = 90.2
-18.6(0.993) + 17.2y = 90.2
-18.3478 + 17.2y = 90.2
17.2y = 90.2 + 18.3478
17.2y = 108.5478
y = 108.5478 / 17.2
y ≈ 6.309
So, the solution to the system of equations is approximately (0.993, 6.309).
Therefore, the correct answer is not d. (2,3). It is actually not among the given choices.