When u add it stays the same but for subtraction u change the sign.
Example: 2- (-5)=7
Answer:
7) 230mm
8) 98m
Step-by-step explanation:
7)
7x+8+6x+6+9x-4 =22x+10
if x is 10 mm, 22(10)+10 =230mm
8) perimeter of rec =2( l + w )
=2 ( 2x-5+2x+6 ) = 8x + 2
if x is 12 metres, 8(12)+2 =98m
Answer:
Step-by-step explanation:
hope this helps!
Answer: 9.70%
Step-by-step explanation:
The formula to find the percentage error is given by :-
Given : Actual mass of zinc oxide used by pharmacist = 28.35 g
Estimated mass of zinc oxide used by pharmacist =31.1 g
Now, 
i.e. 
i.e. 
Hence, the percentage of error on the basis of the desired quantity.= 9.70%
c = cost of food/med for cats
d = cost of food/med for dog
y = total cost/spent
What you know:
y = 6c + d [has 6 cats and 1 dog]
c = 2/3d - 5 [cost for cat is 5 less than 2/3 cost for dog]
y = $195
y = 6c + d
Substitute/plug in what you know, plug in (2/3d - 5) for c and 195 for y
195 = 6(2/3d - 5) + d Distribute/multiply 6 into (2/3d - 5)
195 = 4d - 30 + d Combine like terms
195 = 5d - 30 Add 30 on both sides of the equation
225 = 5d Divide 5 on both sides
$45 = d
