It's a simultaneous equation:
Steps:
1.Number the equations..
a+b=77 -1
a-b=13 -2
2. Choose what variable you want to use. In this case I would use the "b". Since the signs in front of the "b's" are different, add the two equations together
a + b = 77
+ + +
a (-b) = 13
Which gives;
2a = 90
Then solve to find a:
2a=90
a= 90/2
a=45
3.Then plug the "a" value into any of the original equations to find the "b" value. I would use equation 1 since the all the variables are positive.
a + b = 77
(45) + b = 77
b=77-45
b=32
4.Solution
a=45
b=32
Answer:
Each goal gives 5 points and a penalty costs 7 points.
Step-by-step explanation:
Let a penalty cost = x points
And a goal gives = y points
Ben makes 7 goals and 2 penalties ending the game with 21 points,
7y - 2x = 21 --------(1)
Alyssa makes 10 goals and 8 penalties ending the game with (-6) points,
10y - 8x = -6
5y - 4x = -3 --------(2)
Equation (1) multiplied by 2, then subtracted from equation (2),
(5y - 4x) - 2(7y - 2x) = -3 - 2(21)
5y - 4x - 14y + 4x = -3 - 42
-9y = -45
y = 5
From equation (1)
7(5) - 2x = 21
35 - 2x = 21
2x = 35 - 21
2x = 14
x = 7
Therefore, each goal gives 5 points and a penalty costs 7 points.
1. Correct answer is a (since when you are not given the n values, it is implied that the first value is 1).
3. Correct answer is a (a(n)=-3+4(1-1)=-3).
7. The pattern is to reduce the previous value by 4, thus the 12th term of the sequence is -24 (a(n)=20 - 4(n-1)=20 - 4(12-1)=-24).
8. Missing term is 26 (32+20=52; 52/2=26).
10. Pattern is 625/1=625; 625/5=125; 125/5=25; 25/5=5, thus. the 10th term is 1/3125 (answer a).
Answer 9x^2
Step-by-step explanation:
3x^2+6x^2=9x^2
