Respuesta :
1) 9x+4y=11
3x-10y=-2 -----> 9x-30y=-6
9x+4y=11
-(9x-30y=-6)
------------------
34y=17
y=1/2
9x+4(1/2)=11
9x=9
x=1
2) 4x+3y=21 -----> 8x+6y=42
5x+2y=21 -----> 15x+6y=63
8x+6y=42
-(15x+6y=63)
-7x=-21
x=3
4(3)+3y=21
3y=9
y=3
Answer:
1) x=1 and y=1/2
2) x=3 and y=3
Step-by-step explanation:
1) 9x+4y=11;3x−10y=−2
Step: Solve9x+4y=11for x:
9x+4y=11
9x+4y+−4y=11+−4y(Add -4y to both sides)
9x=−4y+11
9x/9= −4y+11/9
(Divide both sides by 9)
x= −4/9y + 11/9
Step: Substitute
−4/9y + 11/9 for x in 3x−10y=−2:
3x−10y=−2
3(−4/9y + 11/9)−10y=−2
−34/3y + 11/3 =−2(Simplify both sides of the equation)
−34/3y + 11/3 + −11/3 = −2+ −11/3 (Add (-11)/3 to both sides)
-34/3y = -17/3
-34/3y -17/3
---------- = --------- ( Divide both sides by ( -34)/3 )
-34/3 -34/3
Step: Substitute 1/2 for y in x= -4/9y + 11/9
x= -4/9 + 11/9
x= -4/9 ( 1/2) + 11/9
x=1 ( Simplify both sides of the equation)
Answer:
x= 1 , y= 1/2
2) 4x+3y=21 ; 5x+2y=21
Step: Solve4x+3y=21for x:
4x+3y=21
4x+3y+−3y=21+−3y(Add -3y to both sides)
4x=−3y+21
4x
4
=
−3y+21
4
(Divide both sides by 4)
x=
−3
4
y+
21
4
Step: Substitute
−3
4
y+
21
4
forxin5x+2y=21:
5x+2y=21
5(
−3
4
y+
21
4
)+2y=21
−7
4
y+
105
4
=21(Simplify both sides of the equation)
−7
4
y+
105
4
+
−105
4
=21+
−105
4
(Add (-105)/4 to both sides)
−7
4
y=
−21
4
−7
4
y
−7
4
=
−21
4
−7
4
(Divide both sides by (-7)/4)
y=3
Step: Substitute3foryinx=
−3
4
y+
21
4
:
x=
−3
4
y+
21
4
x=
−3
4
(3)+
21
4
x=3(Simplify both sides of the equation)
Answer:
x=3 and y=3
Hope this really helped! Pls mark brainliest thx :)