Question

Hi, please help me, explain please

If the number 2 is one of the roots of the equation 2x ^ 2 + 3x + k = 0 ,then find the value of k.​

Answer 1

Explanation:

1) substitute x with 2

2*2^2 + 3*2 + k = 0

2) solve the equation

8 + 6 + k = 0

k + 14 = 0

k = -14

Answer 2

`\sf \hookrightarrow \: {2x}^(2) + 3x + k = 0 \\ \sf \hookrightarrow \: 2 {(2)}^(2) + 3(2) + k = 0 \\ \sf \hookrightarrow \: 2 * 4 + 6 + k = 0 \\ \sf \hookrightarrow \: 8 + 6 + k = 0 \\ \sf \hookrightarrow \: 14 + k = 0 \\ \sf \hookrightarrow \: k = - 14`