solve and comparison:
a)4x-9y=4
6x+15y=-13
im so lost!!!!!
multiply the first by 3 to get
12x - 27y = 12 or 12x = 27y + 12
multiply the second by 2 to get
12x + 30y = -13 or 12x = -30y - 13
now "compare" the 12x of the first part with the 12x of the second part to get
27y + 12 = -30y - 13
etc.
"elimination" would be the more practical way of doing this one.
just subtract my two altered equations
why do you hav to multiply it by three though?
I wanted the x's to have the same coefficient.
you had
4x .... and
6x ....
think of finding a "common denominator"
and remember, what I do to one side of any equation, I must do to the other side.
thank u so much !!!!!!
i'm so dead!
Type the ordered pair that is the solution to these equations.3x - 2y = 8 2x + 5y = -1.
To solve the system of equations, you can use either the substitution method or the elimination method. Let's use the elimination method to solve this system of equations:
a) 4x - 9y = 4
6x + 15y = -13
Step 1: Multiply both sides of the first equation by 15 to make the coefficients of y in both equations equal:
15(4x - 9y) = 15(4) --> 60x - 135y = 60 (equation 1)
Step 2: Multiply both sides of the second equation by 9 to make the coefficients of y in both equations equal:
9(6x + 15y) = 9(-13) --> 54x + 135y = -117 (equation 2)
Step 3: Add equation 1 and equation 2 together:
(60x - 135y) + (54x + 135y) = 60 + (-117)
Combine like terms:
60x + 135y + 54x + 135y = -57
Simplify:
114x + 270y = -57 (equation 3)
Step 4: Divide equation 3 by 3 to simplify the equation:
(114x + 270y) / 114 = -57 / 114
Simplify:
x + (270y/114) = -1
Since the equation is already simplified, we can substitute this value into either equation 1 or equation 2 to solve for y. Let's use equation 1:
4x - 9y = 4
Substitute x + (270y/114) = -1 into this equation:
4(x + (270y/114)) - 9y = 4
Now, we simplify and solve for y:
4x + (1080y/114) - 9y = 4
Multiplying through by 114 to clear the fraction:
4(114x) + 1080y - 9(114y) = 4(114)
456x + 1080y - 1026y = 456
Simplify:
456x + 54y = 456
Now, we have a new equation (456x + 54y = 456) and the original equation (114x + 270y = -57). We can solve this system of equations using the substitution method or elimination method again.
At this point, we have simplified the system of equations but haven't found the values for x and y. If you provide me with further information or clarify the question, I can help you find the solution and make a comparison.