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.
In algebra the notation is basically just a number, for example, 10, and we take it to the 10th power, you just take the decimal at the end of the 10 and move it 10 spaces to the right, if the number is negative you will move the decimal to the left 10 spaces, the 10th power is a variable and is different with every question
To find the average speed for the whole race, you just have
to add the speed from a starting marker and the speed from the turnaround
marker going back and divide it by 2 since there are only two speeds involved.
10 m/s + 16m/s = 26 m/s / 2 = 13 m/s
Therefore, the average speed for the whole race is 13 m/s.
Answer:
look at the picture i have sent
Answer:
I think its A but not 100 percent sure
Step-by-step explanation:
