4x²+4x-35=0
factor: (2x+7)(2x-5)=0
2x+7=0, or 2x-5=0
2x=-7 or 2x=5
x=-3.5 or x=2.5
I don't see any rounding necessary in this case.
when you factor ax²+bx+c, you take the two factors of a and the two factors of c, one factor of a times one factor of c, the other factor of a times the other factors, the sum of the two products make b.
in this case, the factors of 4 is 2 and 2, the factors of -35 is -5 and 7. I line them up in the following way:
2 -5
2 7
then I multiple them diagonally, the top left 2 multiplying the bottom right 7=14, and the other 2 multiplying -5=-10, 14 and -10 make a sum of 4.
if you don't get the desired sum, switch the factors up and down till you have the right combination. Note: Do not switch left and right.
I hope this makes sense to you.
The correct answer is option 4! you have a good day as well
Answer: The primary cause of low pH in precipitation over northeastern North America is sulphuric acid (H2SO4) from industrial and urban emissions of sulphur dioxide (SO2). Nitric acid (HNO3) generated from emissions of nitrogen oxides (NOx) is a significant contributing factor in this region.
Step-by-step explanation:
x=7 or x=-6
Let's solve your equation step-by-step.
0.25x2−0.25x−10.5=0
For this equation: a=0.25, b=-0.25, c=-10.5
0.25x2+−0.25x+−10.5=0
Step 1: Use quadratic formula with a=0.25, b=-0.25, c=-10.5.
x=
−b±√b2−4ac
2a
x=
−(−0.25)±√(−0.25)2−4(0.25)(−10.5)
2(0.25)
x=
0.25±√10.5625
0.5
x=7,−6