Question

Solve using the quadratic formula. Show all work. Write each solution in simplest form. No decimals.

Answer 1

Option D. {7 + i√71 / 20, 7 – i√71 / 20}

Explanation:

10m² – 7m + 3 = 0

Using formula method, the solution to equation can be obtained as follow:

10m² – 7m + 3 = 0

Coefficient of m² (a) = 10

Coefficient of –7m (b) = –7

Constant (c) = 3

m = –b ±√(b² – 4ac) / 2a

= – –7 ±√((–7)² – 4 × 10 × 3) / 2 × 10

= 7 ±√(49 – 120) / 20

= 7 ±√(–71) / 20

Recall:

–17 = –1 × 17

Thus,

7 ±√(–71) / 20 = 7 ±√(–1 × 71) / 20

Recall:

√–1 = i

Thus,

7 ±√(–1 × 71) / 20 = 7 ± i√71 / 20

= 7 + i√71 / 20 or 7 – i√71 / 20

Therefore, the solutions to the equation are:

{7 + i√71 / 20, 7 – i√71 / 20}