# When twice a number is decreased by 5 the result is 27. What is the number?The sum of two numbers is 39. If the other one is 6 less than twice the other,what are the numbers?8 more than 1/2 of a number is 41. What is the number?

2
by ryanbrylesolerbryle

2014-11-11T20:50:42+08:00
-when twice a number is decreased by 5 the result is 27
Let x be the number
2x - 5 = 27
2x = 27 + 5
2x = 32
x = 16
-the sum of two numbers is 39. if the other is 6 less than twice the other, what are the numbers
let x be the first number and y be the other number
x + y = 39  (1st equation)
y = 2x - 6  (2nd equation)
Substitute the 2nd equation to the 1st equation
x + y = 39
x + (2x - 6) = 39
x + 2x - 6 = 39
x + 2x = 39 + 6
3x = 45
x = 15
Substitute x = 15 to the 2nd equation
y = 2x - 6
y = 2(15) - 6
y = 30 - 6
y = 24
-8 more than 1/2 of a number is 41
let x be the number
1/2x + 8 = 41
1/2x = 41 - 8
1/2x = 33
x = 2(33)
x = 66

thank you so much
2014-11-11T22:39:12+08:00
1.) 2x-5=27 2x= 27+5 2x/2=32/2 x=16 2.) 2y-6=39 x+ 22.5= 39 2y= 39+6 x= 39-22.5 2y/2=45/2 x= 16.5 y= 22.5