How do you solve for L? L=5B L+7=3(B+7)

2 answers:

7 0

Remember
a(b+c)=ab+ac
and you can do ANYTTHING to be
L=5B
divide both sides by 5
L/5=B
sub L/5 for B in other equation
L+7=3((L/5)+7)
distribute
L+7=(3L)/5+21
minus 7 both sides
L=(3L)/5+14
time boths sides by 5
5L=3L+70
minus 3L both sides
2L=70
divide 2
L=35

TEA [102]3 years ago

4 0

You first plug in 5B for L in the 2nd equation and you get 5B+7=3B+21 (distributive property). Then you simplify and you get B = 7. Then you plug 7 back in the first equation and get L = 35.

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Read 2 more answers

Francine Flicka found a bargain when she bought a lawn mower. She paid the store's clerk three $20 bills and received him $7.45

adoni [48]

Answer:

$48.97

Step-by-step explanation:

Let p represent the marked price of the mower. Then the price with tax is ...

with tax = p + 7.3%×p = 1.073p

The amount Flicka paid is the amount tendered less the change she received, so is ...

3×$20 - 7.45 = with tax = 1.073p

To find p, we can divide by its coefficient:

(3 × $20 - 7.45)/1.073 = p ≈ $48.97

The selling price before taxes was $48.97.

_____

<em>Comment on the problem</em>

If you check the answer, you find the amount with tax is ...

$48.97 × 1.073 ≈ $52.54481 ≈ $52.54

so the change Flicka would have received would have been $7.46, not $7.45. If the price were $48.98, then the change would have been $7.44. There is no price at which the mower can be marked that will make the total with tax come to $52.55. There is no solution to this problem.