This may not be very pretty.
(2x + 5) * (2x + 5) expanded is (use foil)
F = 4x^2
O = 2x * 5 = 10x
I = 2x + 5 = 10x
L = 25
Total = 4x^2 + 20x + 25
(x + 3)(x + 3) = x^2 + 6x + 9 by the same method
(2x + 7)(2x + 7) = 4x^2 + 28x + 49 Same method.
4x^2 + 20x + 25 + x^2 + 6x + 9 = 4x^2 + 28x + 49
5x^2 + 26x + 34 = 4x^2 + 28x + 49 Collect everything on the left.
x^2 - 2x - 15 = 0
(x - 5)(x + 3) = 0
x + 3 will have no meaning.
x - 5 = 0
x = 5
2x + 5 = 2*5 + 5 = 15
x + 3 = 5 + 3 = 8
2x+ 7 = 2*5 +7 = 17
Check
15^2 + 8^2 = 17^2
225 + 64 = ? 289
289 = 289
a = 15 <<<<< answer
b = 8 <<<<< answer
c = 17 <<<<< answer
Answer:
(5 x (-20)) * (100 x (0.7))
30 - 5d - c + 3d
In this equation there are two numbers which have the letter d with them. These would be like terms.
You have -5d + 3d which equals -2d
The simplified form would be 30 -2d -c
877.71=877.7
when rounding, look at the previous place value to determine if you should round up or down :)
Answer:
The solution of the system of equations is (11, 12)
Step-by-step explanation:
∵ The price of each student ticket is $x
∵ The price of each adult ticket is $y
∵ They sold 3 student tickets and 3 adult tickets for a total of $69
∴ 3x + 3y = 69 ⇒ (1)
∵ they sold 5 student tickets and 3 adults tickets for a total of $91
∴ 5x + 3y = 91 ⇒ (2)
Let us solve the system of equations using the elimination method
→ Subtract equation (1) from equation (2)
∵ (5x - 3x) + (3y - 3y) = (91 - 69)
∴ 2x + 0 = 22
∴ 2x = 22
→ Divide both sides by 2 to find x
∵ 
∴ x = 11
→ Substitute the value of x in equation (1) or (2) to find y
∵ 3(11) + 3y = 69
∴ 33 + 3y = 69
→ Subtract 33 from both sides
∵ 33 - 33 + 3y = 69 - 33
∴ 3y = 36
→ Divide both sides by 3
∵ 
∴ y = 12
∴ The solution of the system of equations is (11, 12)