Answer:
This is a complete lesson with instruction & exercises for 5th grade about multiplying decimals by decimals. The interpretation for multiplying a decimal by a decimal is to think of it as taking a fractional part of a decimal number (the symbol × translates to "of"). The lesson compares multiplication by a decimal to scaling & shrinking a stick. Lastly, it shows the common shortcut to decimal multiplication (multiply as if there were no decimal points; the answer has as many decimals as the factors have in total.)
In the video below, I explain the rule for multiplying decimals (put as many decimal digits in the answer as there are in the factors.) I explain where this rule comes from, using fraction multiplication. The lesson continues below the video.
Answer:
5
Step-by-step explanation:
5
Answer:
PV = 8 VT = 4√3
Step-by-step explanation:
Given
PT = 4
With reference angle 30°
perpendicular (p) = 4
hypotenuse (h) = ?
sin 30° = p/h
1/ 2 = 4 / h
cross multiply
h = 8
with reference angle 60°
perpendicular (p) = ?
hypotenuse (h) = 8
sin 60° = p/h
√3 / 2 = p / 8
Cross multiply
2p = √3 * 8
p = 4 √3
Hope it's correct and would be helpful :)❤
Area=legnth times width or
a=lw
if w=4/5l
and a=320 then subsitute 320 for a dn 4/5l for w
320=4/5l times l
multiply both sides by 5 to clear fraction
1600=4l times l
ad like terms
1600=4l^2
subtract 1600 from both sides
0=4l^2-1600
try and factor because if you have xy=0 then x and/or y=0 so
difference of 2 perfect squares where
if you have a^2-b^2 then that equals(a-b)(a+b) so
0=(2l)^2-(40)^2=(2l-40)(2l+40)
so 2l-40=0
add 40 to both sides
2l=40
divide by 2
l=20
if
2l+40=0
subtract 40 from both sides
2l=-40
divide 2
l=-20
since meausrements of real objects cannot be negative, wediscard this number
l=20 is thhe true legnth s
subsitute
w=4/5l
w=4/5(20)
w=80/5
w=16
legnth=20
width=16
