a) 3x -2y = 10
x + 3/4y = 17.5
b) 2/3x - sqroot(y) = 18
1/5x + 1/2y = 7
2006-12-05 23:43:08 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
a)
3x -2y = 10
x + 3/4y = 17.5
3x + 9/4y = 52.5
17/4y = 42.5
y = 170/17 = 10
x + 7.5 = 17.5
x = 10
2006-12-05 23:47:15 · answer #1 · answered by oscarD 3 · 0⤊ 0⤋
a)
3x -2y = 10 -----a
x + 3/4y = 17.5-----b
multiply b by 3
3x +9/4y = 52.5-----c
a-c
3x-2y-(3x+9/4y) = 10-52.5
-4.25y= -42.5
y= 10
subst y=10 into a
3x-20=10
3x=30
x=10
x=10; y=10
b)
2/3x - sqroot(y) = 18-----a
1/5x + 1/2y = 7-----b
sq a
4/9xsq-y= 324-----c
multibly b by 2
2/5x+y=14-----d
c+d
4/9xsq-y+(2/5x+y)=324+14
4/9xsq+2/5x=338
multiply eq by 45
20xsq +18x-15210=0
oh well. i am stuck.. hope it doesnt confuse u (:
2006-12-06 08:59:50 · answer #2 · answered by pigley 4 · 0⤊ 0⤋
a)
3x-2y=10
4x+3y=70 (2)*4
multiplying the first by 3 and the second by2 and adding
9x-6y=30
8x+6y=140
17x=170
x=10
sub in 3x2y=1
30-2y=10
-2y=-20
y=10
solution set(10,10)
2006-12-06 07:46:41 · answer #3 · answered by raj 7 · 0⤊ 0⤋