Answer:
$ 5.65
Step-by-step explanation:
let the cost of a pencil and a ruler be $p and $r respectively.
4p +r= 1 -----(1)
6p +3r= 2.10
divide by 3 throughout:
2p +r= 0.70 -----(2)
Q: 3p +13r= ?
(1) -(2):
(4p +r) -(2p +r)= 1 -0.70
4p +r -2p -r= 0.30 <em>(</em><em>expand</em><em>)</em>
2p= 0.30 <em>(</em><em>simplify</em><em>)</em>
p= 0.30 ÷2 <em>(</em><em>÷</em><em>2</em><em> </em><em>on</em><em> </em><em>both</em><em> </em><em>sides</em><em>)</em>
p= 0.15
subst. into (1):
4(0.15) +r= 1
r +0.60= 1
r= 1 -0.60
r= 0.40
cost of three pencils and thirteen rulers
= 3p + 13r
= 3(0.15) + 13(0.40)
= 0.45 + 5.20
= $5.65
Answer:
6 how do you not know this?
Step-by-step explanation:
8 = 1
16 = 2
24 = 3
32 = 4
40 = 5
48 = 6
maths. the more you know
Answer:
Step-by-step explanation:
- x² + 6x - 3 = 0
- x² + 2*3*x + 3² - 3 = 3²
- (x + 3)² = 12
- x + 3 = ± √12
- x + 3 = ± 2√3
- x = 2.196, x = -8.196
Answer:
Step-by-step explanation:
x=3
there would be a 14 percent chance of you or your friend winning