The answer is B; x=18 and y = -20
Proof:
Solve the following system:
{4 x + 3 y = 12 | (equation 1)
{7 x + 5 y = 26 | (equation 2)
Swap equation 1 with equation 2:
{7 x + 5 y = 26 | (equation 1)
{4 x + 3 y = 12 | (equation 2)
Subtract 4/7 × (equation 1) from equation 2:
{7 x + 5 y = 26 | (equation 1)
{0 x+y/7 = (-20)/7 | (equation 2)
Multiply equation 2 by 7:
{7 x + 5 y = 26 | (equation 1)
{0 x+y = -20 | (equation 2)
Subtract 5 × (equation 2) from equation 1:
{7 x+0 y = 126 | (equation 1)
{0 x+y = -20 | (equation 2)
Divide equation 1 by 7:
{x+0 y = 18 | (equation 1)
{0 x+y = -20 | (equation 2)
Collect results:
Answer: {x = 18, y = -20
It’s ba + 2b - 2a + ab
B times a is ba
B times b is 2b
-a times a is -2a
-a times -b is ab
Whenever it’s a negative and a positive, it will be a negative integer or letter.
But when there’s two negatives will be a positive integer or letter.
Answer: the percent of the books in the store that are discounted is 60%
Step-by-step explanation:
Let x represent the total number of books in the bookstore. If the bargain books make up 18 percent of the total number of books in the store, it means that the total number of bargain books in the bookstore is
18/100× x = 0.18x
Let y represent the number of books that have been discounted. 30 percent of the books that have been discounted are called bargain books. This means that
30/100 × y = × 0.18x
0.3y = 0.18x
y = 0.18x/0.3 = 0.6x
The percentage of the number of books that have been discounted would be
0.6x/x × 100/= 0.6×100 = 60%
A= Area
l= length
w= width
l= w-3cm
A= l*w
A= 53cm²
53= l*w
(plug in value of length)
53= (w-3)(w)
0=w²-3w+53
Use the quadratic formula:
(in the pictures attached)
w= about 9cml=9-3=
6cmAny questions?
Step-by-step explanation:
4x 3.5 + 4x 2.3
14 + 9.2
= 23.2
