A). 4x^2-4x-15=0
b). 5w^3=40w^2-80w
2007-05-02 08:37:41 · 9 answers · asked by regine f 1 in Science & Mathematics ➔ Mathematics
A). 4x^2-4x-15=0
quadratic equation:
Delta = 4*4 - 4*4*(-15) = 4*4*(1+15) = (16)^2
x1 = [4 + sqrt(Delta)]/[2*4] = [4 + 16]/[2*4] = 5/2
x2 = [4 - sqrt(Delta)]/[2*4] = [4 - 16]/[2*4] = -3/2
b). 5w^3=40w^2-80w
w1 = 0
or 5 w^2 = 40 w - 80
5w^2 - 40w +80 = 0
w^2 - 8 w + 16 = 0
w^2 - 2*4*w + 4^2 = 0
(w - 4)^2 = 0
double solution: w = 4
In total: 3 solution: (one single and two double) w1 = 0, w2 = w3 = 4
2007-05-02 08:45:20 · answer #1 · answered by roman_king1 4 · 0⤊ 0⤋
A. 4x^2 - 4x - 15 = 0
(2x - 5)(2x + 3) = 0
2x - 5 = 0 2x - 3 = 0
x = 5/2 x = -3/2
B. 5w^3=40w^2-80w
5w^3-40w^2+80w=0
5w(w^2 -8w +16) = 0
5w(w - 4)(w - 4) = 0
5w = 0 w - 4 = 0
w = 0 w = 4
2007-05-02 08:50:01 · answer #2 · answered by Anonymous · 0⤊ 0⤋
aaaa). 4x^2-4x-15=0
quadratic equation:
Delta = 4*4 - 4*4*(-15) = 4*4*(1+15) = (4*16)^2
x1 = [4 + sqrt(Delta)]/[2*4] = [4 + 4*16]/[2*4] = 17/2
x2 = [4 - sqrt(Delta)]/[2*4] = [4 - 4*16]/[2*4] = -15/2
b). 5w^3=40w^2-80w
w1 = 0
or 5 w^2 = 40 w - 80
5w^2 - 40w +80 = 0
w^2 - 8 w + 16 = 0
w^2 - 2*4*w + 4^2 = 0
(w - 4)^2 = 0
double solution: w = 4
3 solution: (one single and two double) w1 = 0, w2 = w3 = 4
2007-05-02 08:46:45 · answer #3 · answered by Kacper T 2 · 0⤊ 0⤋
A) x= ((4+-sqrt(16+240))/8=(4+-16)/8 =
x= 5/2 and x= -3/2
B) 5w(w^2-8w+16)=0 so
w=0
w=((8+-sqrt(64-64))/2 =4 double root
2007-05-02 08:51:31 · answer #4 · answered by santmann2002 7 · 0⤊ 0⤋
approach A: 5X = 100 and fifty 5 5 x X = 100 and fifty 5 X = 100 and fifty 5/5 X = 31 OR approach B: 5X = 100 and fifty 5 5 x X = 100 and fifty 5 5 = 100 and fifty 5/X X = 100 and fifty 5/5 X = 31 the proper approach is extra elementary, besides the indisputable fact that the bottom is likewise in theory impressive. In exams, the proper approach is the perfect to apply. wish this permits!
2016-12-05 05:54:47 · answer #5 · answered by ? 4 · 0⤊ 0⤋
a) Use quadratic formula or factor out. x=20/8 or -12/8
b) Divide 5w on both sides
w^2=8w-16
subtract 8w-16 on both side
w^2-8w+16=0
Factor out
(w-4)(w-4)=0
w=4
2007-05-02 08:44:05 · answer #6 · answered by UnknownD 6 · 0⤊ 0⤋
a) -3/2 and 5/2
b) 0 and 4
2007-05-02 08:55:15 · answer #7 · answered by Leslie C 2 · 0⤊ 0⤋
A) X=2.5
X=1.5
B)X=4
X=4
Although its against my theory of learning; I have included a link so you can learn to do the equations yourself.
2007-05-02 09:04:47 · answer #8 · answered by clutchdoc 2 · 0⤊ 0⤋
(2x-5)(2x+3)=0
2x-5=0
2x+3=0
2x=5
2x=-3
x=5/2 or x=-3/2
5w^3-40w^2+80w =0
5w(w^2-8w+16)=0
5w(w-4)(w-4)=0
w=4 or w=0
2007-05-02 08:45:16 · answer #9 · answered by Dave aka Spider Monkey 7 · 0⤊ 0⤋