Answer:
D. -12s squared + 11st - 2t squared
Step-by-step explanation:
FOIL:
-3s(4s) - 3s(-t) + 2t(4s) + 2t(-t)
- 12s² + 3st + 8st - 2t²
Simplify.
- 12s² + 11st - 2t²
Answer:
29.3
Step-by-step explanation:
to find average you find the sum of all the minutes she practiced and divide it by the total amount of day she practiced.
first we have to find the sum of the minutes she practiced:
20+30+40+38+25+22+39+22+26+31
this equation is equal to 293 minutes she practiced in total. Now we have to divide this by the total amount of days she practiced whice according to the data is 10! So:
293/10 =29.3
Y=62
X=122
cuz triangles equal 180
500 kg x 90% = 500x 0.9 = 450 kg of Steel is needed.
450 kg x 98% = 450 x 0.98 = 441 kg of iron needed.
450 x 0.02 = 9 kg of carbon is needed for the steel.
50 kg of chromium is needed.
Chromium is 10% carbon, 50x 0.1 = 5 kg of carbon is needed for the chromium.
Total iron = 441 kg
Total carbon = 9 + 5 = 14 kg
Total chromium = 50 kg