
above is the distance formula, plugging your numbers from P(x1,y1) and Q(x2,y2).

or
Given:
The system of equations:


To find:
The number that can be multiplied by the second equation to eliminate the x-variable when the equations are added together.
Solution:
We have,
...(i)
...(ii)
The coefficient of x in (i) and (ii) are 1 and
respectively.
To eliminate the variable x by adding the equations, we need the coefficients of x as the additive inverse of each other, i.e, a and -a So, a+(-a)=0.
It means, we have to convert
into -1. It is possible if we multiply the equation (ii) by -5.
On multiplying equation (ii) by -5, we get
...(iii)
On adding (i) and (iii), we get

Here, x is eliminated.
Therefore, the number -5 can be multiplied by the second equation to eliminate the x-variable.
You can calculate percentages by first finding what 10% of a value is and then what 5 or 1% is. From there you can multiply to find multiples and then add to get the required percentage. The example below shows this.
<span>What is 35% of $40?<span>Step 1<span>What is 10% of $40?10% of $40 = $40 ÷ 10 =<span> $4</span></span><span>10% is a relatively easy percentage and can be found by<span> dividing by 10</span>.</span></span><span>Step 2<span>3 x $4 = $1230% of $40 = $12</span>30% is 3 times ( 3 x) 10% so we multiply what 10% of $40 is by 3</span><span>Step 3<span>What is 5% of $40?5% of $40 = $4 ÷ 2 =<span> $2</span></span><span>5% is half of what 10% is so divide what 10% is by 2 .</span></span><span>Step 4<span>What is 35% of $40?$12 + $2 = $14</span><span>Add what</span></span></span>
So
eq=ellen's quarters
en=ellens's nickles
lq=lola's quarters
ln=lola's nickles
lq/2=eq or lq=2(eq)
2(ln)=en or ln=en/2
en+eq=$6.30 or 630 cents
en+6nickles=eq
so nickle=5 so
5*6=30
630-30=600
number of nicles=number of quarters of lola=600
nickle+quater=30
600/30=20
20 quarters
20+6=26 nickles
elen has 20 quarters and 26 nickles
20 times 2=40 quarters
26 divided by 2=13 nickles
lola has 40 quarters and 13 nickles
40 times 25=1000 cents in quarters
13 times 5=65 cents in nickles
1000+65=1065 cents or $10.65=lola's money