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In Mathematics / Middle School | 2014-05-09

Find all possible values of the given variable:

1. \( h^2 + 5h = 0 \)

2. \( z^2 - z = 0 \)

3. \( m^2 + 13m + 40 = 0 \)

4. \( z^2 - 3z = 0 \)

5. \( q^2 + 7q = 0 \)

6. \( k^2 + 2k = 0 \)

7. \( x^2 - 3x - 70 = 0 \)

8. \( q^2 + 7q - 60 = 0 \)

9. \( z^2 + 9z - 36 = 0 \)

10. \( d^2 - 13d + 22 = 0 \)

Asked by figueroa00841

Answer (2)

1. h 2 + 5 h = 0 h ( x + 5 ) = 0 x = 0 or x + 5 = 0 ∣ − 5 x + 5 − 5 = 0 − 5 x = 0 or x = − 5
2. z 2 − z = 0 z ( x − 1 ) = 0 z = 0 or z − 1 = 0 ∣ + 1 z − 1 + 1 = 0 + 1 x = 0 or z = 1
3. m 2 + 13 m + 40 = 0 a = 1 , b = 13 , c = 40 Δ = b 2 − 4 a c = 1 3 2 − 4 ⋅ 1 ⋅ 40 = 169 − 1600 = − 1431 an d w e kn o w w h e n Δ i s n e g a t i v e , t h eres n o \solution
4. z 2 − 3 z = 0 ( z − 3 ) = 0 z = 0 or z − 3 = 0 ∣ + 3 z − 3 + 3 = 0 + 3 z = 0 or z = 3
5. q 2 + 7 q = 0 q ( q + 7 ) = 0 q = 0 or q + 7 = 0 ∣ − 7 q + 7 − 7 = 0 − 7 q = 0 or q = − 7
6. k 2 + 2 k = 0 k ( k + 2 ) = 0 k = 0 or k + 2 = 0 ∣ − 2 k + 2 − 2 = 0 − 2 k = 0 or k = − 2
7. x 2 − 3 x − 70 = 0 a = 1 , b = − 3 , c = − 70 Δ = b 2 − 4 a c = ( − 3 ) 2 − 4 ⋅ 1 ⋅ ( − 70 ) = 9 + 280 = 289 x 1 ​ = 2 a − b − Δ ​ ​ = 2 3 − 289 ​ ​ = 2 3 − 17 ​ = 2 − 14 ​ = − 7
x 2 ​ = 2 a − b + Δ ​ ​ = 2 3 + 289 ​ ​ = 2 3 + 17 ​ = 2 20 ​ = 10 ( x + 7 ) ( x − 10 ) = 0
8. q 2 + 7 q − 60 = 0 a = 1 , b = 7 , q = − 60 Δ = b 2 − 4 a c = 7 2 − 4 ⋅ 1 ⋅ ( − 60 ) = 49 + 240 = 289 x 1 ​ = 2 a − b − Δ ​ ​ = 2 − 7 − 289 ​ ​ = 2 − 7 − 17 ​ = 2 − 24 ​ = − 12
x 2 ​ = 2 a − b + Δ ​ ​ = 2 − 7 + 289 ​ ​ = 2 − 7 + 17 ​ = 2 10 ​ = 5 ( x + 12 ) ( x − 5 ) = 0
9. z 2 + 9 z − 36 = 0 a = 1 , b = 9 , q = − 36 Δ = b 2 − 4 a c = 9 2 − 4 ⋅ 1 ⋅ ( − 36 ) = 81 + 144 = 225 x 1 ​ = 2 a − b − Δ ​ ​ = 2 − 9 − 225 ​ ​ = 2 − 9 − 15 ​ = 2 − 24 ​ = − 12
x 2 ​ = 2 a − b + Δ ​ ​ = 2 − 9 + 225 ​ ​ = 2 − 9 + 15 ​ = 2 6 ​ = 3 ( x + 11 ) ( x − 3 ) = 0
10. d 2 − 13 d + 22 = 0 a = 1 , b = − 13 , q = 22 Δ = b 2 − 4 a c = ( − 13 ) 2 − 4 ⋅ 1 ⋅ 22 = 169 − 88 = 81 d 1 ​ = 2 a − b − Δ ​ ​ = 2 13 − 81 ​ ​ = 2 13 − 9 ​ = 2 4 ​ = 2
d 2 ​ = 2 a − b + Δ ​ ​ = 2 13 + 81 ​ ​ = 2 13 + 9 ​ = 2 22 ​ = 11 ( d − 2 ) ( d − 11 ) = 0

Answered by Lilith | 2024-06-10

The solutions to the equations provided are computed through factoring where applicable and applying the quadratic formula. The key results are the roots for each equation including cases with no real solutions. Each equation yields specific values that satisfy the given quadratic forms.
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Answered by Lilith | 2025-03-28