11. 3a + b = 5
2a + b = 10
the answer is (--5, 20)
13. 3r - 5s = -35
2r -5s = -30
the answer is (-5, 4)
17. 4x - 3y = 12
4x + 3y = 24
the answer is (4.5, 2)
35. y = 5x
x + 2y = 22
the answer is (2, 10)
2a + b = 10
the answer is (--5, 20)
13. 3r - 5s = -35
2r -5s = -30
the answer is (-5, 4)
17. 4x - 3y = 12
4x + 3y = 24
the answer is (4.5, 2)
35. y = 5x
x + 2y = 22
the answer is (2, 10)
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11. Subtract the second one from the first one. You will have: 3a + b -2a -b = 5 -10
a = -5 and then substituting a in whichever equation you want you find b
13. You do the same thing as before 1st equation - 2nd equation and you find that:
3r -5s - 2r + 5s = -35 + 30 r = -5 and s =4 (3 * (-5) - 5s = -35 => 5s = 20 => s = 4)
17. Now it is better to add the equations to remove 3y. You will have 8x = 36 => x=4.5 and then substitution to find y
35. Now you know that y = 5x and you can substitute right away as following: x + 2(5x) = 22
Thus 11x = 22 => x=2 and y = 5*2 = 10
a = -5 and then substituting a in whichever equation you want you find b
13. You do the same thing as before 1st equation - 2nd equation and you find that:
3r -5s - 2r + 5s = -35 + 30 r = -5 and s =4 (3 * (-5) - 5s = -35 => 5s = 20 => s = 4)
17. Now it is better to add the equations to remove 3y. You will have 8x = 36 => x=4.5 and then substitution to find y
35. Now you know that y = 5x and you can substitute right away as following: x + 2(5x) = 22
Thus 11x = 22 => x=2 and y = 5*2 = 10