小武新家装修,在装修客厅时,购进彩色地砖和单色地砖共100块,共花费5600元.已知彩色地砖的单价是80元/块,单色地砖的单价是40元/块.
(1)两种型号的地砖各采购了多少块?
(2)如果厨房也要铺设这两种型号的地砖共60块,且采购地砖的费用不超过3200元,那么彩色地砖最多能采购多少块?
解:(1)设彩色地砖采购x块,单色地砖采购y块,由题意,得
x+y=10080x+40y<
下列关于现代生物技术的叙述中错误的是 ( )
18-9=____ 96-80=____ 18+8=____ 41-3=____
12-7=____ 84-4=____ 27+9=____ 25-8=____
13-4=____ 75-20=____ 35+8=____ 36-9=____
____
Read and choose. 读下列单词,选出不同类的选项。
① ____ A. panda B. tiger C. lion D. animal
② ____ A. Chinese B. Maths C. Sunday D. Music
③ ____ A. built B. keep C. told D. drank
④ ____ A. children B. library C. restaurant D. school
⑤____ A. jacket B. skirt C. chocolate D. sweater