Answer:
Step-by-step explanation:
2x+y=9
3x+5y=19
I will do this problem in 2 ways. I.)Substitution II.)Elimination
Solution I.) Substitution
We can subtract 2x from both sides in the first equation.
y=9-2x
Now we can substitute the y in the second equation with 9-2x
3x+5(9-2x)=19
-7x+45=19
-7x=-26
x=26/7
y=9-2(26/7)=11/7
Solution II.)Elimination
We can multiply both side of first equation by 5 to get a 5y in both equations.
10x+5y=45
Now because both are positive 5y we just need to do simple subtraction of the 2 equation, each side respectively.
(10x+5y)-(3x+5y)=45-19
7x=26
x=26/7
2*26/7+y=9
y=11/7
Ultimately you get the same answer, both are viable methods, some problems are faster with one method but I recommend mastering both since they are very useful.
Answer:
80.95
Step-by-step explanation:
Percentage increase = 
*100
=> (38-21)* 100/21 = 80.9523%
The answer round it to the nearest 100th = 80.95%
Answer:
r = - 
Step-by-step explanation:
The n th term of a GP is
= a₁ 
where a₁ is the first term and r the common ratio
Here a₁ = 18 and a₆ = - 
, then
18 
= - ( divide both sides by 18 )
= - 
( take the fifth root of both sides )
r = ![\sqrt[5]{-\frac{1}{243} }](https://tex.z-dn.net/?f=%5Csqrt%5B5%5D%7B-%5Cfrac%7B1%7D%7B243%7D%20%7D)
= -
