Answer:1.8(x -1)
2.0.4a -7
Step-by-step explanation:
X^2 - 14 x = 15
(x - 7)^2 - 49 = 15
(x-7)^2 = 64
x - 7 = - or + 8
x = 15 or -1
Just take half o the coefficient of x and subtract it squared as above.
In general
x^2 + ax = b
(x + a/2)^2 - a^2/4 = b
10 squared = 100
10*10=100
X² - 4x - 12 =
x² + 2x - 6x - 12 =
x(x + 2) - 6(x + 2) =
(x + 2)(x - 6)
Jake wants to post a 600 gram parcel and an 800 gram parcel.
He posts them Second Class.
He pays with a £10 note.
How much change should he get?
