Answer:
5
Step-by-step explanation:
Let x be the number of cell phones with keyboards needed.
40% =
=
x+45 = 40 -----1
x+120 = 100 -----2
You would want to make the total of 1 the same as 2.
1×: 2.5+112.5 = 100 -----3
Now 2 and 3 are equal.
x+120 = 2.5x+112.5
Isolate the x and numbers.
120-112.5 = 2.5x-x
Simplify.
1.5x = 7.5
x = × 7.5
x = 5
The manager of the store needs to add 5 more cell phones with keyboards.
Answer:
14 and 16.
Step-by-step explanation:
We know that two consecutive even numbers is 30.
Let's let n be <em>any number</em>.
Then the first <em>even</em> number must be 2n.
This is because n can be any number, either even or odd. However, if we multiply it by 2, this <em>ensures</em> that 2n is even. Remember that any number multiplied by 2 yields an even number.
Therefore, the consecutive even number will be (2n+2). Not (2n+1), because that gives an odd number.
We know that they sum to 30. So, we can write the following equation.
And we solve from there:
So, the value of n is 7.
Therefore, the first even number is 7(2)=14.
And the consecutive even number is 16.
Edit: Typo