Question

Solve the equation z^2+ 3z – 18 = 0.

A. z = –6, z = –3
B. z = –3, z = 6
C. z = 3, z = 6
D. z = –6, z = 3

Answer 1

➣ Assignment:
`\bold{Solve \ Equation: \ z^2+3z-18=0}`

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➣ Answer:
`\boxed{\bold{z=3,\:z=-6}}`

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Explanation: ↓↓↓↓↓

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➤ [ Step One ] Solve Using Quadratic Formula

`\bold{For\:a\:quadratic\:equation\:of\:the\:form\:ax^2+bx+c=0 \ the\:solutions\:are\:}}`

`\bold{x_(1,\:2)=(-b\pm √(b^2-4ac))/(2a)}`

`\bold{a=1,\:b=3,\:c=-18:\quad z_(1,\:2)=(-3\pm √(3^2-4\cdot \:1\left(-18\right)))/(2\cdot \:1)}`

➤ [ Step Two ] Solve Equation

`\bold{(-3+√(3^2-4\cdot \:1\cdot \left(-18\right)))/(2\cdot \:1): \ 3}`

➤ [ Step Three ] Solve Equation

`\bold{(-3-√(3^2-4\cdot \:1\cdot \left(-18\right)))/(2\cdot \:1): \ -6}`

➤ [ Step Four ] Combine Solutions

`\bold{z=3,\:z=-6}`

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`\bold{\rightarrow Mordancy \leftarrow}`