Answer:
262 books sold
Step-by-step explanation:
This is a very vague word problem, but if it truly is just asking the amount of books sold (regardless of music or science), here's how to get the answer:
1. 287+134=421 - first you want to add together the two types of books to get the total amount of books in the store
2. 421-x=159 - create an equation and solve.
3. -x=-262 - follow order of operations and subtract 421 on both sides in order to isolate the variable
4. x=262 - divide each side by -1 to make the variable positive.
If you'd like an easier way, you can just:
1. 421-159=262 - it's easier, but my math teacher would count us wrong if we didn't do equations a specific way. Good luck!
Answer:
B. 3
Step-by-step explanation:
The degree of this polynomial is based on the highest power on the exponents (if there is more than one variable, it is based on the sum)
The highest power is 3, so the degree is 3
11) -x + y = -1 ; 2x - y = 0
y = -1 + x ; 2x - (-1+x) = 0 ⇒ 2x + 1 - x = 0 ⇒x = -1
y = -1 + (-1) ⇒ y = -2
12) -2x + y = -20 ; 2x + y = 48
y = -20 + 2x ; 2x + (-20 + 2x) = 48 ⇒ 2x -20 + 2x = 48 ⇒ 4x = 48 + 20
4x = 68 ⇒ x = 68/4 ⇒ x = 17
y = -20 + 2(17) ⇒ y = -20 + 34 ⇒ y = 14
13) 3x -y = -2 ; -2x + y = 3
y = 3 + 2x ; 3x - (3 + 2x) = -2 ⇒ 3x - 3 - 2x = -2 ⇒ x = -2 + 3 ⇒ x = 1
y = 3 + 2(1) ⇒ y = 3 + 2 ⇒ y = 5
14) x - y = 4 ; x - 2y = 10
x = 4 + y ; (4 + y) - 2y = 10 ⇒ 4 + y - 2y = 10 ⇒ 4 - y = 10
⇒ -y = 10 - 4 ⇒ -y = 6 ⇒ y = -6
x = 4 + (-6) ⇒ x = 4 - 6 ⇒ x = -2
15) x + 2y = 5 ; 3x + 2y = 17
x = 5 - 2y ; 3(5-2y) + 2y = 17 ⇒ 15 - 6y + 2y = 17 ⇒ -4y = 17 - 15
⇒ -4y = 2 ⇒ y = -2/4 ⇒ y = -1/2
x = 5 - 2(-1/2) ⇒ x = 5 + 2/2 ⇒ x = 5 + 1 ⇒ x = 6
Answer:
-6x +10x= 4x
Step-by-step explanation:
-2x(3 - 5x)
-6x +10x= 4x
