Answer:
x is a value that is not yet known
4(7a + 5) = -160
mutiply the bracket by 4
(4)(7a)(4)(+5)= -160
28a+20= -160
move +20 to the other side
sign changes from +20 to -20.
28a+20-20= -160-20
28a= -180
Divide by 28
28a/28= -180/28
x= -180/28
reduce by dividing 4
-180/4= -45
28/4= 7
-45/7 or -6 3/7
Answer : x= -45/7 , x= -6 3/7
Answer:

Step-by-step explanation:
Given

Required
Condition that the roots is in m : n
Let the roots of the equation be represented as: mA and nA
A quadratic equation has the form:

or

We have the roots to be mA and nA.
So, the sum is represented as:


And the product is represented as:


By comparing:

with



So, we have:


Make A the subject:


Substitute 


Multiply both sides by a


Cross Multiply:

Hence, the condition that the ratio is in m:n is

Answer:
In problems involving proportions, we can use cross products to test whether two ratios are equal and form a proportion. To find the cross products of a proportion, we multiply the outer terms, called the extremes, and the middle terms, called the means.
Step-by-step explanation:
In problems involving proportions, we can use cross products to test whether two ratios are equal and form a proportion. To find the cross products of a proportion, we multiply the outer terms, called the extremes, and the middle terms, called the means.
That expression is the expected value of your winnings, or "the average amount you will win (or lose) per game in the long run".