How do you factor #5x^2+15x+10#?

1 Answer
Don't Memorise
Jun 2, 2015

# 5x^2 +15x +10#

We can Split the Middle Term of this expression to factorise it.

In this technique, if we have to factorise an expression like #ax^2 + bx + c#, we need to think of 2 numbers such that:
#N_1*N_2 = a*c = 5*10 = 50#
and,
#N_1 +N_2 = b = 15#

After trying out a few numbers we get #N_1 = 10# and #N_2 =5#
#10*5 = 50#, and #10 + 5= 15#

# 5x^2 +15x +10 = 5x^2 +10x + 5x +10#

# = 5x(x+2) + 5(x +2)#

#(x+2)# is common to both terms

# color(green)((5x+5)(x+2)# , is the factorised form.

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