substitution method
7x +9y= 19
x=25-5y
___________
7(25-5y)+9=19
175-35 +9=19
-175 -175
_______________
-26y= -156
y=6
substitute for x
x=25-5y
x=25-5(6)
x=25-30
x=-5
now substitute
7x+9y=19
7(-5)+ 9(6)=19
-30+56=19
19=19 his part is wrong I believe explain if I need to do this differently?
The last lines...
7(-5)+9(6)=19
-35+54=19
19=19
You made two math errors on yours
Anwers to math week 6 uop
The steps you followed are mostly correct, but there seems to be a small mistake in the final calculation.
Let's go through the solution again:
1. Given equations:
7x + 9y = 19 ...(1)
x = 25 - 5y ...(2)
2. Substitute equation (2) in equation (1) to express y in terms of x:
7(25 - 5y) + 9y = 19
3. Simplify equation (3) by distributing:
175 - 35y + 9y = 19
4. Combine like terms:
-26y + 175 = 19
5. Move 175 to the other side of the equation:
-26y = 19 - 175
-26y = -156
6. Divide both sides of the equation by -26 to solve for y:
y = -156 / -26
y = 6
7. Substitute the value of y (which is 6) back into equation (2) to find x:
x = 25 - 5y
x = 25 - 5(6)
x = 25 - 30
x = -5
8. Finally, substitute the values of x and y into equation (1) to check if it holds true:
7x + 9y = 19
7(-5) + 9(6) = 19
-35 + 54 = 19
19 = 19
It seems that the mistake was in the final calculation of 7(-5) + 9(6), which should give you -35 + 54 = 19 (not -30 + 56 = 19). As you can see, the equation does hold true, indicating that the solution (x = -5, y = 6) is correct.