Answer:
10.2cm
Step-by-step explanation:
Perimeter is the sum of the lengths of all sides.
1st side: 9cm
2nd side: 7.8cm
Perimeter: 27cm
Perimeter = 1st + 2nd +3rd side of a triangle
27cm = 9cm +7.8cm + 3rd side
3rd side = 27cm - 9cm -7.8cm
= 10.2cm
First, Alvin gave Joyce and Sean 2/3 of the remainder, to solve first find the common denominator, which in this case is 24. Then, 1/3=?/24, 24/3=8 so it is 8/24 for the total given by Alvin. Joyce got 5/8, 5/8=?/24, 24/8=3,3 x 5=15, 15/24.
15/24 - 8/24= 7/24 is the answer
20*65 = 1300
That's the price without tax.
Now to find tax:
1300*.035 = 45.5
1300+45.5 = $1345.5
$1345.5 is your total
Let x gallons be the amount of pure antifreeze that should be added to the 30% solution to produce a solution that is 65% antifreeze. Then the total amount of antifreeze solution will be x+3 gallons.
There are 30% of pure antifreeze in 3 gallons of solution, then
3 gallons - 100%,
a gallons - 30%,
where a gallons is the amount of pure antifreeze in given solution.
Mathematically,

Now in new solution there will be x+0.9 gallons of pure antefreeze.
x+3 gallons - 100%,
x+0.9 - 65%
or

Answer: he should add 3 gallons of pure antifreeze.
Answer:
x,y,x = 2,4, -3
Step-by-step explanation: