Look at the system of equations below. If you were to substitute the first equation into the second, what would the result look like?
y = 2x - 4
x - 3y = 7
a).2x - 4 - 3y = 7
b).x - 3(2x - 4) = 7
c).x - 2x - 4 = 7
d).x - 7 = 2x - 4
I really need help with this question, I don't understand it. PLEASE HELP!
x - 3y = 7 but y = 2x - 4 so
x-3(2x-4)=7 which is exactly one of the answers.
thank you so soooo much, i apreciate the help (:
To substitute the first equation into the second equation, you need to replace the variable "y" in the second equation with its equivalent from the first equation.
In the first equation, y is equal to 2x - 4.
To substitute this into the second equation, replace "y" in the second equation with 2x - 4:
x - 3(2x - 4) = 7
Now you need to simplify the expression within the parentheses. To do this, distribute the -3 to both terms inside the parentheses:
x - 3(2x) + 3(4) = 7
Simplify further:
x - 6x + 12 = 7
Combine like terms:
-5x + 12 = 7
Now, you need to solve for x. Move the constant term (12) to the other side of the equation by subtracting 12 from both sides:
-5x + 12 - 12 = 7 - 12
-5x = -5
Finally, divide both sides by -5 to isolate x:
(-5x)/-5 = -5/-5
x = 1
So, by substituting the first equation into the second equation, we found that x = 1.