Step-by-step explanation:
they're is a neat little trick.
but first of all, "roots" means the 0 solutions of the equation. like
ax² + bx + c = 0
there are 2 solutions for x to make the whole expression equal 0.
these are the "roots".
now to the little trick :
when is a multiplication resulting in 0 ?
when at least one of the factors is 0.
and any quadratic expression can be written as multiplication of 2 factors. like
c(x - a)(x - b) = cx² - cax - cbx + cab
what are the "roots" or 0 points ?
either
c = 0
x - a = 0 | x = a
x - b = 0 | x = b
the leading coefficient = 3.
that means nothing else than c = 3.
root = 1 means (x - 1) is one factor.
root = -5 means (x + 5) is the other factor.
so, we have
3(x - 1)(x + 5) = 3x² + 12x - 15
and the equation is
3x² + 12x - 15 = 0
or
3x² + 12x = 15
Answer:
-0.008 or -1/15
Step-by-step explanation:
Answer:
∠3 = 60°
Step-by-step explanation:
Since g and h are parallel lines then
∠1 and ∠2 are same side interior angles and are supplementary, hence
4x + 36 +3x - 3 = 180
7x + 33 = 180 ( subtract 33 from both sides )
7x = 147 ( divide both sides by 7 )
x = 21
Thus ∠2 = (3 × 21) - 3 = 63 - 3 = 60°
∠ 2 and ∠3 are alternate angles and congruent, hence
∠3 = 60°
Paralell to 2x+y=-5
means it has same slope
means it is in form
2x+y=c where we have to find c
convert to slope intercept
minus 2x both sides
xint of 2
xint is where th eline crosses the x axis or where y=0, x=2
2(2)+0=c
2(2)=c
4=c
the equation is 2x+y=4
