How do you use cross products to solve $\frac{30}{6} = \frac{b}{7}$ $30/6=b/7$ ?

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How do you use cross products to solve $\frac{30}{6} = \frac{b}{7}$ $30/6=b/7$ ?

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Answer 1 · 2018-04-11T18:45:25

$b = 35$ $b = 35$

Explanation:

eliminate the denominators so that you can get an idea as to what b will become

$\frac{30}{6} = \frac{b}{7}$ $30/6 = b/7$ cross multiply the denominators by the other numerators

$30 (7) = b (6)$ $30(7) = b(6)$

$210 = 6 b$ $210 = 6b$ divide both sides by 6 to isolate b

$b = 35$ $b = 35$

a faster way to do this is by seeing that $\frac{30}{6}$ $30/6$ equals $\frac{5}{1}$ $5/1$ . take that $5$ $5$ and multiply it by $7$ $7$ to get $35$ $35$

Answer 2 · 2018-04-11T19:17:49

$b = 35$ $b=35$

Explanation:

$given equal fractions ab=cd$ $"given equal fractions "a/b=c/d$

$then a d = b c \leftarrow cross product$ $"then "ad=bclarrcolor(blue)"cross product"$

$using this method to solve the equation$ $"using this method to solve the equation"$

$\Rightarrow 6 b = (30 \times 7)$ $rArr6b=(30xx7)$

$\Rightarrow b = \frac{30 \times 7}{6} = 35$ $rArrb=(30xx7)/6=35$

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How do you use cross products to solve $\frac{30}{6} = \frac{b}{7}$ $30/6=b/7$ ?

2 Answers

Explanation:

Explanation:

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How do you use cross products to solve 306=b730/6=b/7?

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How do you use cross products to solve $\frac{30}{6} = \frac{b}{7}$ $30/6=b/7$ ?