algebra a help?

Question

i don't get these, can someone explain how to do them? thankss


1. the second of the two numbers is 4 times the first. their sum is 50. find the numbers.

2.the second of the two numbers is 45. the first is 9 less than the second. find the numbers.

Answer 1

1. y=4x.
x+y=50.
subbing 4x in for y:.
5x=50
(x,y)=(10,40)

2. y=45
x=45-9=36

Answer 2

If a is the first number and b is the second:

1.
the second of the two numbers is 4 times the first: b=4*a
their sum is 50: a + b =50

so : a + 4*a = 50, that is 5*a = 50, so a=10, and b=4*10=40.

2.
the second of the two numbers is 45: b = 45
the first is 9 less than the second: a = b - 9 = 45 - 9 = 36

Answer 3

Let the first number = x
The second number = 4x

The sum is 50. So first number + second number = 50
x + 4x = 50.
5x = 50
x = 10
The first number is 10, and the second number is 40.

Problem number 2:

2nd number = 45
1st number = 45 - 9

Therefore the two numbers are 45 and 36.

Hope that helps!!

Answer 4

1.) X+4X=50
5X=50
X=10

2.) to find the first number since the second is already given
45-9= 35 so its 45 and 9

Answer 5

1)
first you do
4x + x = 50
5x = 50
x = 50/5 = 10
the firs number is 10 and the second is 40

2)
45 - 9 = 36
the first number is 45 and 36 is the first

Answer 6

for the first question

x + 4x = 50 fill in for "x"
(10) + 4(10) = 50
but if you need to solve for x, you could go x + 4x = 5x,.....therefore 5x = 50 ..... 50/ 5 = 10.

2nd= 45..... 45-9 = 36
you just really have to look at the questions and take your time. think it out, and try to write down, in numbers, what the question is telling you, and fill in "x" or another letter variable for the value(s) you need to find.

Answer 7

ok let's have a variable make up real numbers.

"x" will be the variable

so far we have this
x+4x=50

thats one unknown variable + 4times that number added together equals 50.

we then add like variables.
now we get
5X=50

the opposite of multiplying is dividing.

divide 5 by both sides of the equation so theyre equal.

X=10
----------------------------------------------------------------------
2.

X-9+45=50 (if its the same sum as above)

the unkown number "x" minus 9 +the known 45= 50

you add like terms
-9+45= 36

you now get X+36=50

opposite of addition is subtraction

take away 36 from each side

you now get your answer

X=14




so your answers are

1.X=10
2. X=14

Answer 8

1. 10 and 40

2. 36 and 45

Answer 9

question #1)
x+4x=50
5x=50
x=10

question #2)
45-9=x
36=x
x=36

Answer 10

1. 1st no. is 10 while 2nd no. is 40

2.1st no. is 36 while 2nd no. is 45