Answer:
The cost of each exercise book is 25 sh.
The cost of each pen is 8 sh.
Step-by-step explanation:
Write down the system of equations and then solve.

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The y axis is changed because you added 5. So the vertex would now be (0,5)
Answer:
$5028.4
Step-by-step explanation:
The expression for that investment will be 2500*(1.15)^t where t is in years, the value of the investment will be 2500*(1.15)^5=5028.4
<span>a/b = 3/5 ----- a = (3b)/5
a + b = 136 --- (3b)/5 + b = 136
3b + 5b = 680
8b = 680
b = 85
a = (3b)/5 = (3 * 85)/5 = 51
a = 85 and b = 51</span>