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:
x = 4, x ≠ -1
Step-by-step explanation:
√3x + 4 = x
(√3x + 4)² = x² (Square both sides to get rid of the radical.)
3x + 4 = x²
0 = x² - 3x - 4 (Set everything to 0 by moving everything to one side.)
0 = (x - 4)(x + 1) (Factor.)
x = 4 x = -1
Now we need to check for extraneous solutions:
√3(4) + 4 = 4
√12 + 4 = 4
√16 = 4
4 = 4
√3(-1) + 4 = -1
√-3 +4 = -1
√1 = -1
1 ≠ -1
-1 is an extraneous solution.
Answer:
A
Step-by-step explanation:
account balance on compound interest = principal amount (1+rate/100)^time
here there are t years so toat months are 12t and ad interest is after each 4 months so time is 12t/4 =3t
now total balance = 3545(1.045)^3t
here 3545 is principal amount , rate is( 1.045-1)×100 =4.5% per 4 months and 3t is time so clearly 3t or 3 is a growth factor hence option A
Answer: yes
Step-by-step explanation:
2(4)=8
