You have to multiply by 2
The ratio that is not equivalent is B. 7:15
The reason why it's not equivalent because for the other ratios:
1:5 could be turned into 2:10 by multiplying 1 and 5 by 2.
4:20 could turn into 2:10 by dividing both numbers by 2.
And 8:40 could be divided by 4 to get 2:10.
But you can't do anything to 7:15 to make it 2:10.
I don't see the answer choices, but 2 equations you could use to get eighteen would be:
9 × 2 = 18
OR
9 + 9 = 18
See? Twice a number is eighteen. You can use any of my equations to get eighteen
↑ ↑ ↑ Hope this helps! :D
Answer:
x = -4, 5/2
Step-by-step explanation:
A quadratic can be solved may ways, including graphing, factoring, and the quadratic formula. You can also check possible answers by making use of the relationships between solutions and the coefficients.
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A graph is attached. It shows the solutions to be -4 and 5/2.
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When factored, the equation becomes ...
(2x -5)(x +4) = 0 . . . . . has solutions x=-4, x=5/2 (these make the factors zero)
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Using the quadratic formula, the solutions of ax^2 +bx +c = 0 are found from ...
x = (-b±√(b²-4ac))/(2a)
x = (-3±√(3²-4(2)(-20))/(2(2)) = (-3±√169)/4 = {-16, +10}/4
x = {-4, 5/2}
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For ax^2 +bx +c = 0, the solutions must satisfy ...
product of solutions is c/a = -20/2 = -10
Only the first and last choices have this product.
sum of solutions is -b/a = -3/2
Only the first choice (-4, 5/2) has this sum.
Captain has $30 money
Flame has $20 +$5 =$25
difference =30-25=5
Captain has $5 more money