$3 {x}^{2} + 12x = 15 \\ 3 ({x}^{2} + 4x) = 15 \\ {x}^{2} + 4x = 5 \\ {x}^{2} + 4x = 5 \\ {x}^{2} + 4x + 4 = 5 + 4 \\ {x}^{2} + 4x + 4 = 9 \\ {x}^{2} + 4x + {2}^{2} = {3}^{2} \\ \red{ \bold{ (x + 2)^{2} = {3}^{2}}} \\$

3 0

3 years ago

What substitution Should be used to re-write 26(x^3+1)^2-22(x^3+1)-3=0 as a quadratic function?

mel-nik [20]

Answer:

$x^3+1$

Step-by-step explanation:

$26(x^3+1)^2-22(x^3+1)-3=0$

Comparing to

$A(u)^2+B(u)+C =0$

Where A,B,C are constants

You should see that we need to substitute the $x^3+1$ with u.

7 0

3 years ago

The English alphabet has 20 letters more than one fourth the number of letters in the Greek alphabet. The English alphabet has 2

Black_prince [1.1K]

1/4G+20=26
G=24
I cannot really explain this because it is hard to put into words, but it is correct.

7 0

3 years ago

What is the value of x?

Anarel [89]

Answer: 5

Step-by-step explanation:

By the inscribed angle theorem.

$\frac{9}{15}=\frac{2x-1}{3x}\\\\27x=30x-15\\\\-3x=-15\\\\x=5$

4 0

2 years ago