What is the unit rate of 88 students for 4 classes
1 answer:
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Answer:
Here, b represents one loaf of bread and m represents the one gallon of milk.
As per the statement:
Arah went to the grocery store and bought 4 loaves of bread and 1 gallon of milk for $12.
⇒
It is also given that the next week, Sarah bought 2 loaves of bread and 3 gallons of milk for $13.50.
⇒
Then; system of equation :
.....[1]
.....[2]
Solve for b and m using above system of equations.
Multiply equation [2] by 2 we get;
.....[3]
Subtract equation [1] from [3] we get;
Combine like terms;
Divide both sides by 5 we get;
m = $3
Substitute the value of m in equation [1] we get;
Subtract 3 from both sides we get;
Divide both sides by 4 we get;
b = $2.25
Therefore, cost of one loaf of bread (b) and one gallon of milk (m) are:
$2.25 ad $3
Step-by-step explanation:
the error:
it is stated that
subtract (5x)/(x+7) from both sides
multiply both sides by x + 7
7(x+7) = 49x
7x + 49 = 49x
subtract 7x from both sides to isolate x and its coefficient
49 = 42x
thus, this is only true when 49 = 42x. in order for these two equations to be equal, they must <em>always </em>be true, so this is wrong
the solution:
we want to express 7/x as (something) / (x+7). to do this, we can multiply 7/x by 1.
anything divided by itself = 1. thus, if we multiply both the numerator and the denominator by something that turns x into (x+7), we can do what we want to do.
(x+7)/x * x turns x into (x+7), so we multiply both the numerator and denominator by (x+7)/x to get
substitute this for 7/x in our original problem