Answer:
line 2 of her working
Step-by-step explanation:
when multiplying the brackets out it is a negative times posative so she should have wrote -4 not +4
Answer:
A=2πrh
Step-by-step explanation:
A=2*22/7*4*9
=230
The first step would be to add 3x and 2x i believe but I am not sure
Answer:
must be greater than 7
Step-by-step explanation:
using pythagoras theorem
a^2=b^2-c^2
x^2=15^2-12^2
x^2=225-144
x^2=81
take square root both sides
√x^2=√81
x=9
and 9 is greater than 7
Answer:
22 grams
Step-by-step explanation:
loses 50% of it's mass per 22 years
so after 22 years the mass would be 44 grams
22 years later would leave 50% of 44 grams = 22 grams
