16x+12y+15; 12x-10y=16...I have to decide whether I can use the substitution or the elimination method to solve...
2007-02-04 04:44:04 · 3 answers · asked by aj_izmixedlyk3gumbo 4 in Education & Reference ➔ Homework Help
You can use both, but I'd say that substitution is easiest:
16x + 12y = 15
12x - 10y = 16
Take eqn 1:
16x + 12y = 15
12y = 15 - 16x
y = 5/4 - 4/3x
Substitute into eqn 2:
12x - 10y = 16
12x - 10(5/4 - 4/3x) = 16
12x - 50/4 + 40/3x = 16
76/3x - 50/4 = 16
76/3x = 114/4
x = 114/4 * 3/76 = 1.125
y = 5/4 - 4/3x = 5/4 - 4/3(1.125) = 5/4 - 1.5 = -.25
Check with eqn 2:
12x - 10y = 16
13.5 + 2.5 = 16 (check!)
2007-02-08 04:51:22 · answer #1 · answered by ³√carthagebrujah 6 · 0⤊ 0⤋
lets get rid of x. Multiply the first equation through 2 and the 2d equation through -3. After fixing for y= -a million, lets replace -a million in for y interior the first equation. this supplies x=2. to envision, replace -a million and a pair of interior the 2d equation to make certain that the values artwork for both equations. How do you want them thoughts? 2(3x - 2y = 8)===>6x- 4y=16==>-19y=19==>y=-a million -3(2x +5y = -a million)=>- 6x-15y=3 3x-2y=8==>3x-2(-a million)=8==>3x+2=8==>3x=8-2 ==>3x=6==>x=2 2x+5y= -a million==>2(2)+5(-a million)=4 - 5 = -a million
2016-11-25 01:04:08 · answer #2 · answered by ? 4 · 0⤊ 0⤋
u COULD use either...i would use elimination...multiply 1st by 3 and 2nd by 4...and make 1 of them negative so it'll work
2007-02-04 04:52:49 · answer #3 · answered by igotalltheanswers 2 · 0⤊ 0⤋