Answer:
Step-by-step explanation:
1). x² - 8x
To convert this expression into a perfect square trinomial,
x² - 2(4x) + 4² = (x - 2)²
Therefore , 4² = 16 should be added.
Option (4) is the answer.
2). x² + 2x = 3
x² + 2(1)(x) = 3
x² + 2(1)(x) + 1 = 3 + 1 [By adding 1 on both the sides]
(x + 1)² = 4
x + 1 = ±2
x = -3, -1
Option (1) is the answer.
3). 3x²- 18x = 21
x² - 6x = 7
x² - 2(3x) = 7
x² - 2(3x) + 3² = 7 + 3²
(x - 3)² = 7 + 9
(x - 3)² = 16
x - 3 = ±4
x = -1, 7
Answer:
it might be 28 sorry if it doesn't help.
Answer: 3
90 pages in 30 minutes so divide 90 by 30 and 90 divided 30 = 3
Hope this helps!
Answer:
and 
Step-by-step explanation:
Let
x -----> the number of polyphonic ringtones
y ----> the number of standard ringtones
we know that
-----> equation A
-----> equation B
Solve the system of equations by substitution
Substitute equation A in equation B and solve for y
Find the value of x
Is odd between 5 and 40 is a square number and the digits add to 7.
all the square numbers between there are 9,16, 25, 36
It's not 9, 16 or 36 so it has to be 25
Hope this helps :)
