Answer: 6 cm
Step-by-step explanation:
Hi, to answer this question we simply have to substitute h=10 (height) in the formula given:
h=2.5w -5
Replacing:
10= 2.5w-5
Solving for w (width)
10+5=2.5w
15 =2.5w
15/2.5=w
w =6 cm
In conclusion, the width of a poster that is 10 cm high is 6 cm.
Feel free to ask for more if needed or if you did not understand something.