Quadratic formula is x = -b+ or- sq rt b^2-4ac / 2a
a=2 b=5 c=-3
-5 +or- sqrt 5^2-4(2)(-3) / 2(2)
-5 +or- sqrt 49/ 4
-5 + 7 /4 = 2/4 = 1/2
-5 - 7 /4 = -12/4 = -3
Factoring a*c is 2*-3 =-6
Factors of -6 that add to 5 are 6 and -1
Split 5x into +6x-1x
2x^2+6x-1x-3 and group
2x(x+3)-1(x+3)
(x+3)(2x-1)=0
x+3=0 gives x=-3
2x-1=0 gives x=1/2
138 x ? = 75
? = 75/138 = 0.544(3sf)
so about 54.35% (2dp) decrease
Answer:
11
Step-by-step explanation:
7-(-4) is 11. You must make the subtraction symbol in the middle to addition, since you have 2 negatives. Two negatives = postive. So after you do that it would be 7+4=11
Hope this helped!
