7x+y=6
18 + 7x - 12 + 5x = ?18 - 12+ 7x - 5x = ?6 + 2x = ?
7x + y + z = 6 7x + y + 4z = 9 y + x = 6 Take the first two statements and subtract them. 7x + y + z = 6 7x + y + 4z = 9 _____________ 0 + 0 - 3z = -3 Therefore: z = 1 Then you are left with: 7x + y + 1 = 6 7x + y + 4 = 9 which is impossible, so this is an impossible equation.
x2 + 7x + 9 = 3 ∴ x2 + 7x + 6 = 0 ∴ (x + 6)(x + 1) = 0 ∴ x ∈ {-6, -1}
7x+6 = -3x-24 7x+3x = -24-6 10x = -30 x = -3
9x+6 = 7x+18 9x-7x = 18-6 2x = 12 x = 6
4x+6-7x+9=18-3x+15=18-3x=3x=-1
x2 + 7x = 2x2 + 6 x2 - 2x2 + 7x = 6 -x2 +7x - 6 = 0 or alternatively x2 - 7x + 6 = 0
7x+y=6
18 + 7x - 12 + 5x = ?18 - 12+ 7x - 5x = ?6 + 2x = ?
Do you mean: 5x + 9 - 7x + 6 = x - 18 If so, you can solve this question at this manner: -2x + 15 = x - 18 3x = -3 x = -1
6
x=6
7x + y + z = 6 7x + y + 4z = 9 y + x = 6 Take the first two statements and subtract them. 7x + y + z = 6 7x + y + 4z = 9 _____________ 0 + 0 - 3z = -3 Therefore: z = 1 Then you are left with: 7x + y + 1 = 6 7x + y + 4 = 9 which is impossible, so this is an impossible equation.
Presumably this is an equation in which the value of x is to be found. 7x+8 = 4x-10 7x-4x = -10-8 3x = -18 x = -6
x2 + 7x + 9 = 3 ∴ x2 + 7x + 6 = 0 ∴ (x + 6)(x + 1) = 0 ∴ x ∈ {-6, -1}
7x + y = 6 y = 6 - 7x dy/dx = 0-7 = -7 Slope = -7