-4x + y = 6
-5x - y = 21
add both of them
-9x = 27
x = -3
(-4*-3) + y = 6
-12 + y = 6
y = 18
23 stones will be needed (you have to round up, since you can't have a fraction of a stone)
Answer:
d.
Step-by-step explanation:
if x varies directly as y,
x = ky
8 = 12k
12k = 8
k = 8/ 12
k = 2/3,
x = 2/3 y
now substitute the value of any of the numbers of each pair, and check if it works:
for e.g, find x when y = 15
x = 2/3y
x = 2/3 × 15
x = 10
since you obtain x = 10 when y = 15, the pair is a possible corresponding value of x and y. now do the same for the rest .
ii) x = 2/3y
x = 2/3 × 3, when y = 3
x = 2
hence, this is also a possible pair of x and y values.
iii) x = 2/3y
x = 2/3 × 9 when y = 9
x = 6
again, a possible pair of x and y values.
iv) x = 2/3y
x = 2/3 × 20 when y = 20
x = 40/3
here, when y = 20, x is not 15. it is 40/3.
thus, it can be determined that this is not a possible pair of x and y values.
please try to understand and have a great day!
Solution: (2,8)
Using the elimination method set up the system of equations like:
y = x + 6
y = 3x + 2
Eliminate the x-variable by multiplying the top equation by -3
-3y = -3x -18
y = 3x + 2
Combine terms:
-2y = -16
-y = -8
y = 8
Plug in 8 to one of the first equations for y
8 = 3x + 2
6 = 3x
x = 2
Solution: (2,8)
Answer: x = 15
Step-by-step explanation:
First, we will have to acknowledge that Angle M is a complementary angle (that means that it is 90 degrees) meaning that 2x° + 4x° will equal 90 degrees. So, let’s set up this equation.
90 = 2x + 4x
90 = 6x
=
15 = x
Therefore, the x is 15.