<span>The quadratic formula is the solution of the quadratic equation. There's other ways to solve it, but the quadratic formula the easiest/most convenient.
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Answer: -8
Step-by-step explanation: When it says f(x), all you have to do is find value x on the coordinate plane and look up or down until you find a point that runs through that x value. In this case, if you draw a line on x=5, you can see that it goes across a point that has a y value of -8, which is your answer.
2.7 = 27/10
27/10 = x/12
cross multiply
10x = 324
divide both sides by 10
x = 32.4
Answer:
There must be 35 red marbles.
Step-by-step explanation:
This question can be solved using a rule of three.
A probability is the number of desired outcomes divided by the number of total outcomes.
The probability of randomly choosing a red marble is 7/9.
This means that for each set of 9 marbles, 7 must be red.
There are 45 marbles in total in the bag and each is equally likely to be chosen. Work out how many red marbles there must be.
How many red marbles out of 45?
7 red - 9 marbles
x red - 45 marbles

Simplifying by 9


There must be 35 red marbles.