X + 2y = 3 ----------- (1)
x - y = 6 ------------(2)
Equation (2) - (1) :
-3y = 3 // ║x - x = 0 ║;║ - y - 2y = -3y║ ; ║6 - 3 = 3 ║
y = -1 // ║ ÷ (-3) on both sides ║
Substitute y = -1 into equation (2) :
x - y = 6 // ║ Equation 2║
x - ( -1 ) = 6 // ║ Sub y = -1 into the equation║
x + 2 = 6 // ║ open the bracket ( - ) ( -) = + ║
x = 4 // ║ Take away 2 from both sides║
Answer: x = 4, y = -1
Answer:
20:a , a=48
Step-by-step explanation:
5*4=20, 12*4 = 48
Simple mathematics, you multiple 5 by 4 to get 20, do the same thing to 12.
Answer:
The next score he needs to have an overall average of 79 is 89.
Step-by-step explanation:
Gary earned an average score of 77 on his 5 quizzes . The number of score he needs to have an average of 79 can be calculated below.
average score = 77
number of quizzes = 5
sum of Garry score = a
a/5 = 77
cross multiply
a = 77 × 5
a = 385
let
the next score he needs be b to score an average of 79
average = 79
number of quizzes = 6
385 + b/6 = 79
cross multiply
385 + b = 474
b = 474 - 385
b = 89
The next score he needs to have an overall average of 79 is 89.
2(7÷10)×1÷3+4÷15=1.4×0.33+0.267
=0.462+0.267
=0.729(0.73)
The answer is -3.5
hope this helps, and have a fantastic day
