A punch contains 60% of grape juice and the rest is lemon - lime soda ( 2 liters).
Part A:
An equation is:
0.6 x + 2 = x,
where x stays for the liters of punch.
Part B:
x - 0.6 x = 2
0.4 x = 2
x = 2 : 0.4
x = 5 liters
Grape juice = 5 - 2 = 3 liters.
Answer: There are 3 liters of grape juice in the punch.
8.40/3 = £2.80 each
...............
= 3/5(x) + 3/5(x) + 2/5
= 6/5(x) + 2/5
= 2/5 (3x+1)
I hope that is what you are looking for.
If we were to foil
after experieence
we know
ax²+bx+c=0
and
in form
(ax+b)(cx+d)=0
if we expand it, we get
acx²+bcx+adx+bd=0
or
(ac)x²+(bc+ad)x+(bd)=0
compare to
ax²+bx+c=0
we notice that the middle terms (x terms) are
b=(bc+ad)
so
in form
(2x-1)(1x+5)
b=bc+ad=(-1*1+2*5)=-1+10=9
b=9
or you could just expand it