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In Mathematics / Middle School | 2014-09-06

How do you solve these algebra questions?

1. Solve for [tex]m[/tex]:
\[ 2m^2 - 7m - 3 = 0 \]

2. Solve for [tex]b[/tex]:
\[ 4b^2 + 8b + 7 = 4 \]

3. Simplify:
\[ 5\sqrt{80a^2} \]

4. Simplify:
\[ -6\sqrt{150r} \]

5. Rationalize the denominator:
\[ \frac{2}{\sqrt{3}} \]

6. Simplify:
\[ \frac{\sqrt{6}}{5\sqrt{3}} \]

Asked by Roxaunna

Answer (2)

2 m 2 − 7 m − 3 = 0 a = 2 ; b = − 7 ; c = − 3 Δ = b 2 − 4 a c → Δ = ( − 7 ) 2 − 4 ⋅ 2 ⋅ ( − 3 ) = 49 + 24 = 73 x = 2 a − b ± Δ ​ ​ → x = 2 ⋅ 2 7 ± 73 ​ ​ = 4 7 ± 73 ​ ​ ​
4 b 2 + 8 b + 7 = 4 4 b 2 + 8 b + 7 − 4 = 0 4 b 2 + 8 b + 3 = 0 4 b 2 + 2 b + 6 b + 3 = 0 2 b ( 2 b + 1 ) + 3 ( 2 b + 1 ) = 0 ( 2 b + 1 ) ( 2 b + 3 ) = 0 ⟺ 2 b + 1 = 0 or 2 b + 3 = 0 2 b = − 1 or 2 b = − 3 b = − 2 1 ​ or b = − 2 3 ​ ​
5 80 a 2 ​ = 5 80 ​ ⋅ a 2 ​ = 5 16 ⋅ 5 ​ ⋅ ∣ a ∣ = 5 ⋅ 16 ​ ⋅ 5 ​ ⋅ ∣ a ∣ = 5 ⋅ 4 ⋅ 5 ​ ⋅ ∣ a ∣ = 20∣ a ∣ 5 ​ ​
− 6 150 r ​ = − 6 25 ⋅ 6 r ​ = − 6 25 ​ ⋅ 6 r ​ = − 6 ⋅ 5 6 r ​ = − 30 6 r ​ ​
3 ​ 2 ​ = 3 ​ 2 ​ ⋅ 3 ​ 3 ​ ​ = 3 2 3 ​ ​ ​
5 3 ​ 6 ​ ​ = 5 1 ​ ⋅ 3 ​ 6 ​ ​ = 5 1 ​ 3 6 ​ ​ = 5 1 ​ 2 ​ = 5 2 ​ ​ ​

Answered by Anonymous | 2024-06-10

To solve the first two equations, use the quadratic formula and factorization. The simplifications involve extracting square roots and rationalizing denominators. Each step follows algebraic rules to arrive at simplified forms or solutions.
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Answered by Anonymous | 2024-12-26