Question

. Solve the equation (2x + 1)(x + 4) = 22
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Answer 1

Answer:(2x+1)(x+4)=22

We move all terms to the left:

(2x+1)(x+4)-(22)=0

We multiply parentheses ..

(+2x^2+8x+x+4)-22=0

We get rid of parentheses

2x^2+8x+x+4-22=0

We add all the numbers together, and all the variables

2x^2+9x-18=0

a = 2; b = 9; c = -18;

Δ = b2-4ac

Δ = 92-4·2·(-18)

Δ = 225

The delta value is higher than zero, so the equation has two solutions

We use following formulas to calculate our solutions:

x1=−b−Δ√2ax2=−b+Δ√2a

Δ−−√=225−−−√=15

x1=−b−Δ√2a=−(9)−152∗2=−244=−6

x2=−b+Δ√2a=−(9)+152∗2=64=1+1/2