Answer:
1 knife cost £6.6
Explanation:
Simultaneous equation is;
4x = y ----------(equation 1)
12y + 16x = 105.64 ----------- (equation 2)
Rewrite equations:
4x=y;16x+12y=105.64
Step: Solve4x=yfor y:
4x=y
4x+−y=y+−y(Add -y to both sides)
4x−y=0
4x−y+−4x=0+−4x(Add -4x to both sides)
−y=−4x
−y/−1 = −4x/−1
(Divide both sides by -1)
y=4x
Step: Substitute 4x for y in 16x+12y=105.64:
16x+12y=105.64
16x+124x=105.64
64x=105.64(Simplify both sides of the equation)
64x/64 = 105.64/64
(Divide both sides by 64)
x=1.650625
Step: Substitute 1.650625 for x in y=4x:
y=4x
y=(4)(1.650625)
y=6.6025(Simplify both sides of the equation)
1 knife cost = 4x = 4(1.65) = 6.6
∴ 1 knife cost £6.6