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solve for x by completing the square x^2 + 4x - 12

(x+2) 2 -16 = 0 (x+2) 2 = 16 x+2 = -4 or +4 x = 2 or -6
ER
Answered by Eden R. • Maths tutor
2887 Views

y is directly proportional to (x-1)^2. When x=5, y=4. Find y when x=7.

The trick to finding y in this question is to interpret the clue in the question of 'directly proportional'. Directly proportional means that the y and the (x-1) 2 scale by the same amount. Another way of sa...
JS
Answered by Jonathan S. • Maths tutor
11458 Views

Show that (x+1)(x+2)(x+3) can be written as ax^3+bx^2+cx+d

Start by multiplying any 2 brackets together: (x + 1)(x + 2): Split the 1st bracket: x(x+2) + 1(x+2) = x^2 + 2x + x + 2 = x^2 + 3x + 2 Then multiply that answer with the last bracket: (x + 3)(x^2 + 3x + 2): ...
RS
Answered by Rushab S. • Maths tutor
4253 Views

A solution to the equation 2x^2-3x-17=0 lies between 2&3 use method of trail and improvement to find the solution

Sub 2.5 into equation it returns 6.75 so x<2.5 sub 2.25 it returns -0.96875 so 2.25<x<2.5 sub 2.4 it returns 3.448 so 2.25<x<2.4 sub 2.3 it returns 0.434 so 2.25<x<2.3so to 1 dp x=2.3 wo...
DC
Answered by Daniel C. • Maths tutor
4102 Views

Please solve (x+3)(x+4)=20 for x

Expand the double bracket (x+3)(x+4) first: 1) (x)(x)= x^2, 2) (x)(4)=4x ,3) (3)(x)=3x, 4) (3)(4)=12write expanded equation:x^2+4x+3x+12=20simplify and equate the right hand side to zero:x^2+7x-8=0solve for ...
CM
Answered by Caitilin M. • Maths tutor
2933 Views