5a-b = 17 3a+2b =5?

Question

5a-b =17
b= 17-5a
3(a) + 2(17-5a) =5
3a +34 -10 a =5

whats the rest?

Answer 1

5a-b = 17 3a+2b =5?

5a-b =17
b= 17-5a (you failed to consider the sign of b)
3(a) + 2(17-5a) =5
3a +34 -10 a =5
--------------------------------------------------------------------------------
You have an idea on how to do it. Let me illustrate further:

5a-b = 17 equation (1)
3a+2b =5 equation (2)

Solve for a using equation (2)
3a + 2b = 5
3a = 5 -2b
a = 5-2b / 3

Substitute a in equation (1)
5a - b = 17
5(5-2b/3) - b = 17
25 - 10b / 3 - b = 17
Multiply both sides of the equation by 3:
25 - 10b - 3b = 51
Combine similar terms, and transpose 25 to the other side of the equation:
-13b = 26
Divide both sides of the equation by -13:
b = -2

Substitute the value of b in equation (2)
3a + 2b = 5
3a + 2(-2) = 5
3a - 4 = 5
Add 4 to both sides of the equation:
3a = 9
Divide both sides of the equation by 3:
a = 3

To check, substitute the value of a and b to equations (1 & 2)

5a-b = 17
5 (3) - (-2) = 17
15 + 2 = 17

3a+2b =5
3(3) + 2(-2) = 5
9 - 4 = 5

Answer 2

OK good until now you can find the value of (a) from the second equation
3a +34 - 10a =5
3a -10a = 5 - 34
-7a = -29
7a = 29
a = 29 / 7
Now the value we found putting it in first equation to get the value of (b)
5(29 / 7) - b = 17
-b = 17- 145 / 7
-b = 119 / 7 - 145 / 7
-b = -26 / 7
b = 26 / 7
Therefor a = 29/7 and b = 26/7

Answer 3

3a+10a-34=5
13a-34=5
13a=39
a=3

b is equal to 5a-17 NOT 17-5a (mixed up minus sign)
5(3)-17=b
b=-2

Answer 4

Is the first line two equations so-
5a-b=17
3a+2b=5
so you would solve the equation by elimination or substitution you tried substitution right, solve the equation by elimination its so much easier that way [if you need to use substitution im sorry but your screwed because its so complicated and frankly i dont think you can substitute it, the answer is
b=-2
a=3
i think im right because it does satisfy both equations but i could be wrong
i would put the equation and solution in here but you wont be able to learn it if i did if for you but if you still need help add me in [e-mail] or reply to this answer [if you can?] im not that hot in math ethier but im willing to help besides i need the yahoo points for my own questions Lol hope i helped

Answer 5

4a=b+6->(a million) 3a-2b=2->(2) from equation (a million) 4a=b+6 a=(b+6)/4 positioned this fee of (a) in equation (2) 3(b+6)/4-2b=2 (3b+18)/4-2b=2 (3b+18-8b)/4=2 -5b+18=8 -5b=8-18 -5b=-10 b=2 positioned fee of (b) in (a million) 4a=2+6 a=8/4 a=2.

Answer 6

once you have 3a+34-10a=5, you can combine like terms by adding 3a and -10a,a nd you get -7a.. so

-7a+34=5.... sub 34 from both sides, you cancel it out from the left side and end up with 5-34 on the right and you have

-7a = -29... then divide both sides by -7, and you have a=29/7

hope it helped.. gl

Answer 7

10a - 2b = 34
3a + 2b = 5-----ADD
13a = 39
a = 3

9 + 2b = 5
2b = - 4
b = - 2

a = 3 , b = - 2

Answer 8

typing

Answer 9

-7a=-29
a=29/7

Answer 10

easy.
a=3
b=-2

now go study and do your own homework so you can pass sixth grade math.